Old forum notes on engine troubleshooting

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Old Delphi forum notes extracted by FastJeff on troubleshooting engines...

 

I am the frustrated owner of a 1976, 32' Express with FWC motors.  I dewinterized both engines with no problems. Both started and ran fine, but the port engine fails to start one day.  I hit the red reset button atop the port engine and she started and ran fine.  I made it to the gas dock and shut them both down, after which the port engine decided not to start again.  Batteries are fine.  I replaced the ignition switch and she started the first time and ran.  I shut her down and went home.  The next day...nothing! A friend with a meter confirmed the ignition switch is good.  I replaced solenoid...nothing!  Not even a click.  When the key is turned the gauges power up.  It appears the coil is getting warm when the key is on. Has anyone experienced these symptoms? 

 

 

 

Questions one should ask to diagnose the above problem:
1. Does the starter grind at all?  If not, your neutral interlock switch (on the trans), or the crappy wiring to it, could be the culprit.

 

2.  Does the starter crank, but the motor does not start?  If that happens, you need to pull the coil wires from the cap, ground it to the manifold, and see if there's spark. Sometimes we have to be a Sherlock Holmes at times to find out what's happening.

 

 

 

Answers from the frustrated boat owner:

 

The starter does not crank at all. There is not so much as a click.  I don't know why I've not considered the neutral switch.  Good Call.  I'll check that tomorrow.  That was a major headache in my last boat

 

 

 

More suggestions:

 

If your starter bendix was screwed up I think you would at least hear something. If you don't hear even a click, it probably is the neutral switch, or the electrical connection to it.

 

 

 

I have a 1982 37' double cabin with twin 360 engines and 19x19 props. Engines run great: new electronic ignition packs, plugs, timed, etc. Start, idle and run as smooth as silk.  Problem is that at 2800 rpm, in sync, the port engine uses 1/3% more fuel. Each engine feeds direct from a separate tank (no crossover). What’s your best guess? Choke not opening? Getting into the four-barrel phase too soon? Wrong carb jets? The starboard engine gets about 1 mile per gallon, where the port about .66 miles per gallon (at this same 2,800 rpms) with the bow trimmed down and showing about 16-17 knots. Seems to be on good plane with flat wake and not logy.

 

 

 

Have you checked your distributors to make sure that your advance is working properly (getting full advance)? I would also look into the carburetor to see if the secondaries are opening.

 

 

 

I would first check the advance of the distributor. If it isn't advancing properly it will definitely burn more fuel. You should get full advance, around 20 degrees (plus the initial 5 degrees of timing) at 2,000-2,500 rpm. Also if possible while underway at cruise speed remove the flame arrestor and make sure the choke is open. Note if the engine gains speed with the flame arrestors off--I have seen some engines need more air than the arrestors were giving them. BE CAREFULL of the nut and anything else loose, you don't want it sucked in the engine. If the distributor checks out and the carb is open and looks to be working a compression test of the engine would be in order. If the engine checks out with 140 lbs. compression and cylinders are even, the prop would be the next place to look. It could be damaged. Usually you know this because that engine won't tach out with the other engine or in the case of a damaged blade there would be a vibration. 

 

 

 

The original carbs that were on my engines were 700 cfm Carter AFB carbs. I installed the 625 cfm on both engines (Carter AFBs new from Northern Auto) The original primary jets are .101 with metering rods #16-541 that has three steps/.061-.058-.053 sizes. The secondary jets are .086. On the new carbs the primary jets were .098 with metering rods of only two steps, not three, and they have .068-.047 steps. The secondary jets were .101--way too big! If you want to go with the 750 cfm carbs they are really rich, but they will work. My buddy put one on his 318. It works fine but is rich. It pukes excess fuel and carbon on the water when he starts it cold with choke.(Note: Improper choke adjustment!)  Seems to run fine at cruise and at WOT. At this time for my 318 engines my primary jets are .101 with metering rods stepped at/.071 and .047 and for the secondary jets .086. Also the springs that I have controlling the secondary opening are RED, which equals 5 inches of vacuum to open. This is pretty standard for 318's but can be changed for any application or engine size. I am currently replacing my 318's with 360s and will be rejetting my carbs in the spring. Would be glad to pass on that info then also. The carbs on your engines most likely are square bores, with all 4 ports equal size. The new ones are different in that they have smaller primaries and larger secondaries. Not a problem. Carter and Chrysler used many different applications over the years.  Have you tried to run the boat at cruising speed and have someone block the two vent tubes coming off the primary side of the bad engine side and see if the performance picks up? You have to remove the flame arrestor to do this and be very careful not to hurt yourself. Also make sure that the secondaries are not opening faster on one engine then on the other. You need a vacuum gauge to check this out on both engines. They should be the same. You can fix that by changing the springs under the pistons that control the status of the metering rods during engine vacuum operation by accelerating or decelerating the throttles. Hope some of this helps.

 

 

 

Carb rebuild kits are available at quite a few places here in Michigan. A new carb rebuild kit usually runs around $20-25. When doing your own you need to verify that all the passages to jets, vents, pullovers and accelerator circuits are clear and not clogged. Replace any worn metering rods, non-matched springs for the metering rods or worn jets in the primaries. Also make sure that all gaskets and venturies and installed correctly when reassembling.

 

 

 

On the crossover passage in the intake, some came from the factory open and some closed! On my 318's they were blocked from the factory. You would have to pull your intake manifolds to verify this situation. The cross over is located in the middle of the intake below the plenum chamber of the intake. If you look where your choke rod goes into the intake on the right side of the carb and the cover is held down by a small bolt, your passage in right under that location and travels from cylinder head to cylinder head. This is not too hard of task to pull off. Only thing you need is a set of intake gaskets, you don't even have to pull the distributor.

 

 

 

You can check the crossover sometimes by simply putting your fingers on the raised section under the choke pull off. If it gets warm fairly quickly than you are probably open and OK. If it never warms up it is probably plugged up. Some were blocked off but almost all that had a thermal choke pull off had small plates with a restrictor hole to limit the amount of exhaust gases heating the base of the carb. This was necessary to help eliminate vapor lock that I believe that some early units experienced.

 

 

 

I looked at a 360 engine with the intake off. On the left cylinder head the crossover gasket is completely open and the gasket on the right cylinder head is blocked except for a hole 1/2 inch in diameter. This is to slow the flow down to heat up the intake. When this gets plugged there is no flow and the engine runs rich since the choke doesn’t open all the way. Check the right side for heat; if not you may have a blocked passage.

 

 

 

Our 1975 Express Flybridge 32' Marinette has developed a rather bad port engine oil leak while running. Both engines run well for having 1750 hours on them.  I have a question on Chrysler 318's: If it turns out to be a rear seal, .can the rear seal be replaced without hauling the engine out of the bilge? (No!) I realize the trans would have to be removed, but I think I could accomplish that, especially since the Express has a big open cockpit. (The oil pan also has to come off.) I will follow the following regimen to see if I can determine where the leak is coming from:

 

 

 

I will pressure wash the bilge under the errant engine.
I will clean and dry the engine as best as possible
I will clean and dry the bilge under the engine as best as possible
I will lay down some brown butcher paper covering the bilge under the engine and trans.
I will run the engine and see where the drops show up.

 

 

 

I know exactly how you feel. I own an 83 Sedan Bridge with 318s and had the same problem with both engines. Used to run the last few years with oil absorbent diapers under each engine at the rear main seal area. Also with these engines sitting at 13 degree angle doesn't help. Direct drive 1:1. I also had 1720 hours on my engines and they ran fine too. Got tired of it and pulled both engines this year and installed new ones. Your diagnostics of finding the leaks is right on. Also look at the distributor area, sometimes the gaskets leak there and where the engine oil line runs from the rear of the block to the manifold where the engine oil pressure switch is. I also found that engine oil pan gaskets deteriorate over time no matter how much you try to tighten them. It’s not cork, its paper. This is on the large cast aluminum type pan. Another area to check is the valve cover gaskets.

 

 

 

Check is the oil filter adapter on the 318. The adapter bolts to the block with a large bolt and it has a gasket under it. This gasket has given at leaked on at least four boats I know of and we all thought was a faulty rear seal. It’s hard to find but try to start the engine and, while very cold, look at it and also hold a white rag under the oil filter and against the block. On cold start with thick oil it usually shows up the most. Just a thought and it is quite regular on some of the boats over here. Of course the gasket is a marine item and isn't used in automotive that I have been able to find.

 

 

 

Found this same problem on my buddy’s Silverton. He also had an oil leak but his was very obvious. It was in the same place that you described. The large main bolt was loose! If you can't find gaskets for the adaptor they can be purchased, and for that matter all of the engine gaskets can be purchased from Basic Power (www.basicpower.com). I have purchased many Chrysler marine parts from them including complete engine gasket sets. I'm in Michigan and they send through the mail within 3 days.

 

 

 

I also had some leaks that came from the oil sensor located by the distributor.   A mechanic told me to use truck oil sensors and it stopped completely.  Oil pressure read the same.

 

 

 

Are your engines setting at an angle? Chrysler intake manifolds are like big sewers and most of the fuel will run to the rear cylinders if they are at 13 degree angle. Front cylinders always run leaner. Two seasons ago, I had to replace BOTH engines with rebuilds because of burned-through pistons. The forward-most piston in one engine, the second forward piston in the other. Happened simultaneously at WOT. Neither an experienced yard mechanic or independent surveyor could pinpoint the cause. But both suspected bad gas or water in the gas.  A friend suggested that the forward pistons run hot naturally because of the angle at which the engines are mounted, coolant doesn't get up front. There wasn't any forewarning. I don't recall hearing any clicking coming from the engines. Cause is still a mystery.  Check whether your insurance company will cover you since this is a sudden, catastrophic failure, not a routine maintenance/wear and tear event. Mine assisted in covering much of the replacement cost.

 

 

 

Engine coolant should not be an issue here unless you have air leaks in your pickup side. The cooling systems work efficiently when everything is right. I have never experienced hot spots in the upper cylinders unless running very lean, not because of water in a raw water cooled system. I did some experimenting on spark plugs a few years ago. My 318's called for RN9Y'S, this is a cold plug (dissipates heat very quickly, and has a short porcelain and electrode sticking out of bottom). I noticed that the four upper (forward) cylinders would run lean and the four rear cylinders ran rich! I left the RN9's in the upper four cylinders and ran RN12's in the lower four cylinders. Now all cylinders were burning equally (by reading the plugs). My engines set at 13 degree angle in a 32 FBSDN with 1 to 1 direct drives. Last year I installed new engines and all new accessories including two new Carter AFB carbs, 625cfm. I totally recalibrated the carbs primary idle and low speed circuits and I am currently running RN12's in all cylinders.  I have forty hours on these engines and have made two WOT runs with no problems. I may look at going slightly colder on the plugs after my next WOT run next weekend. The engines should be pretty well broken in by now.

 

 

 

My "good" engine (starboard, that burns 20 % less fuel) has a carb that won't adjust properly at idle--it's got a minor flooding condition. The plugs run dark gray to black.  The "bad" engine, the port mill that burns 20 % more gas, has a perfect running carb. Its plugs are running light gray to white. (If it had a bad ignition wire, one of those plugs would run dark, but no.)  Both engines start and run fairly equally.  (Update:  The problem was a dirty flame arrestor.)

 

 

 

How did you determine that your port engine burns more fuel than the starboard one? I have a 1989 32 sedan and I thought that too, based on the amount of fuel required to fill each tank. My setup has a fuel-balancing manifold with petcocks that can regulate the fuel flow from the two tanks. In my boat, both engines and the gen-set draws fuel from this manifold. When mine was using a lot more fuel out of one tank than the other, I closed down partially on the petcock in the line coming from the tank that was running lower at refill. After a couple of tries, I got it pretty close to even. I sync my two engines at cruise with digital tachs to within 20 rpm of each other, so synchronization is not much of a concern.  Could this be the cause of your issue? I guess what I'm saying is, that the apparent difference in fuel consumption rates between the two engines may not be accurate if you're basing it on how much it takes to refuel each tank, unless, of course your setup is different than mine.  The fuel petcocks are overhead (on the bottom side of the sedan sole) at the aft end of the center engine hatch. One could crawl around in that for years on his hands and knees and not know they were there.

 

 

 

On average a Marinette in optimum running condition, ideal weather, etc. will get about 1.4 mpg according to what I’ve read in forum. So lets take 1.2 mpg X 50 = 60 miles with both tanks a grand total of 156 miles running on fumes.  This method could be done for under $500 with no danger to passengers or vessel with spilt fuel from 5 to 10 jerry cans, about what it would take to make it worth while, lashed about the decks, 5 gal. = 6 miles this method about $120 + lashing materials. Then there’s the gas caddy that hold 15 gal. = 18 mi. @ roughly $225 with pump etc. but this is about the same dilemma as jerry cans except little neater?? Wives tale has it that if you run one engine at higher speeds for long distances you have stop the spinning of idle engines prop & shaft as it’s suppose over heat the trans in idle engine due to no cooling effect from pumps now this is hear say someone in forum may be more informed on this subject? Then with prop drag & helm having to be held over to port or starboard would it be worth it running on one engine?? Just a few tidbits for thought. I’m sure you research the distances between Ports where fuel is available this should give you a vague idea on how much extra fuel you may need to carry especially in the foreign countries. I sure would hate to be towed or buy fuel at sea.

 

 

 

That 25% leeway is great advice cause what can happen will happen. I think that’s how the saying goes. That cuts avg. mpg to.09 - 1 x gal.

 

 

 

Chrysler distributors are known for their moisture problem in the distributors. It plays hell on the steel springs for the centrifugal advance weights. You can pull the distributor out and have it repaired at any good auto repair shop. They will probably put it on a machine to reset the centrifugal advance curve after they rebuild it. They will have to replace the springs. [one large & one small, not much difference to the untrained eye] Make sure that you make a note were the rotor is pointing before you pull the distributor out of the engine. If you decide to change the springs yourself, put the dist in a vise remove the plate that holds the points or sending unit to expose the springs and counter weights. You will be surprised at all the rust in there! You will need to use some penetrating oil to free up the counter weighs, everything need to move freely in order for the springs to work properly. After everything is CLEAN, dry and free moving, get yourself some SPRAY anti seize compound made by Loctite [silver in color] and give the springs, counter weights and attachment linkage a good spray down. Do this before you reinstall the plate that holds the points. I did this procedure about four years ago and I have not had a problem with moisture yet.

 

 

 

I've got a question regarding the distributors on my Chrysler 360's. Past year I had a problem with my starboard engine. It would run fine up to 2,000 rpms and then it would have a dead spot when pushing the throttle forward until a certain point where the engine would suddenly rev up to where it should be running. Then I would pull back the throttle down to put it in synch with the port engine. The mechanic that works on my boat checked my distributors and said that they are pretty corroded under the rotor and that the springs aren't in very good shape. As he explained it there are magnets (weights, actually) that spread out as the rpm's pick up to advance the timing. He speculated that this could very well be the problem on the starboard engine. Does this sound right? He recommended that we start here since the springs definitely need attention and reset the timing on both engines. If this doesn't work than he said possibly rebuild carb and accelerator pump.

 

 

 

I remember reading about a trick to keep moisture out of Chrysler
Engines. There is a vent on side of distributor for air, you would have to install some thing to attach a hose to and run the hose to the spark arrestor that would draw air out of distributor. This was supposed to keep the distributor clear of moisture. Some day I may try it

 

 

 

Thanks for the info on this. The mechanic has already removed the old distributors yesterday and is in the process of replacing them with the same type. There was a lot of rust and the springs were definitely not reusable. Even the bottom plate in the distributor was too corroded to reuse. Amazing what the moisture can do. Next time around maybe I'll give it more consideration and change it to electronic ignition (Note: It already is) and do away with the springs. One thing nobody has mentioned thought is whether or not this has any major impact on fuel economy and would it have an effect on the way my starboard engine would seem to have a dead spot when pushing the throttle up from 2000-3000 rpms. Once I get the throttle almost all the way forward the engine would speed up and then I would back it down to match the rpm's of the port engine.

 

 

 

When I re-did mine, I was not to interested in fuel economy (fuel was $1.29 or so a gallon) as the performance of the engines & being able to ideal them down to a 1 to 2 mph.(trolling speeds) But as far as can recall I believe the fuel consumption did get better I couldn’t tell you by how much? The performance increased dramatically and I was able to synchronize engines very easily. The dead spots do sound electrically related more then fuel. I think you hit the nail on the head with the distributor rebuild, well let’s hope there’s not a next time may this solve your dilemma.

 

 

 

One of the first things I did was to get rid of those original small fuel filters on my Marinette. Not sure but I think the original were only filters and small at that. I have a big standard throw away like an oil filter it also removes water. I redid fuel lines to approved hose and last year put in two new carburetors. It was worth it for the old ones are almost worn out. I had them rebuilt by a friend but they need some throttle bushings and other parts that eventually wear out and are not in the rebuild kits.

 

 

 

NAPA sells a nice, in-line filter that you can splice into the line just before the carb. The size to get is 5/16 inch.

 

 

 

I also replaced copper fuel lines with marine-rated rubber hose. I used a spin on fuel filter water separator. You need the mount for the spin on filter. I also put remote oil filters in.  These two things sure made Maintenance easier.
Found number for the oil filter OMC 502905.

 

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It is possible and easy to pull the trans without pulling engine? Yes. I have done it twice while boat was in water (starboard trans).  You disconnect shaft and support rear of engine (hydraulic jack under header). Remove what ever else you need to such as exhaust hose.  Take off rear engine mounts and only loosen front mounts, then jack up rear of engine enough to pull off trans.
Keep in mind you have to realign shaft after reinstalling and setting
(to take a set) for 24 hours. I one had my trans out when I had engines out for rebuild trans looked so good all my mechanic did was to install new seals in trans.  But next year when we ran boat the starboard trans leaked we had it out twice more while boat was in water, we could never find any thing wrong but second time it did stop leaking.

 

 

 

Changing cap, rotor and plugs in the port engine made the horrible transmission noise in my motor disappear. Haven't been able to duplicate the sound since the tune up. Took the vessel out for a shakedown, and it performed flawlessly. Not a knock or a noise from the transmission!  Sounded great, in fact. I am greatly relieved, to say the least! (Note: A rough idle will cause the damper plate--that connects the flywheel to the trans—to rattle loudly.)

 

 

 

I had an intermittent problem with one engine where it would die while cruising. Once I would get it restarted it would only idle. After leaving it off for a half hour I could get some cruising rpms but not much. The next time I would go down to the boat it would run fine. Fuel pressure checked fine--until I rigged it up so I could read the gauge at 3,000 rpm under load. Fuel pressure would drop to zero and then the engine would die. Apparently there was a weak spring in the fuel pump that would start to float at higher rpms. Very annoying!

 

 

 

Regarding your camshaft/timing: The engine would not idle well with a badly installed or wrong camshaft. Lack of distributor advance will prevent an engine of revving up. Your problem is most likely fuel delivery or timing.

 

You need to determine TDC on #1 cylinder. Take the coil wire off the distributor for safety. First determine which is #1 (the left front in all cases). Take the plug out of that cylinder and rotate the engine until the cylinder is at the top. Use something that cannot be dropped into the cylinder and will not damage the piston by rocking the crank back and forth you should be able to approximate TDC This will let you know where the timing mark should be and you can tell if you have the correct mark. Even if there isn't a correct one you can mark on the engine where you think it should be and this will be somewhat useful.  You would be surprised at how far the timing can be off yet the engine will still run. They will have poor torque with late timing but will idle smoothly. One suggestion would be to set the timing at idle by ear and slowly advance it until the engine runs rough.

 

 

 

I too had an "engine won't run over 2,000 rpm" issue. Turned out to be quite simple: I replaced the little fuel filter where the fuel line enters the carb. It has cropped up twice over the years, same engine. I think the coupling at the filter takes a 1" wrench. (A much better fix is to install a large, metal, in-line can filter after the fuel pump.)

 

 

 

I put my engine on top dead center last night and was doing all of the suggestions I have received. The engine is now TDC and the mark on my harmonic balancer is 30 to 40 degrees off. Could this be contributing to all of my engine problems? (No, since it won’t run.)

 

 

 

You either have the wrong # 1 cylinder or the wrong timing mark. The harmonic balancer and crank/piston cannot be installed wrong (like the camshaft can). You might have the wrong timing cover (mixed parts from LH & RH Rotation engines).

 

 

 

There's a slim chance the cam is installed improperly. I would iron out the timing. There are two basic things that you can screw up on installing a cam. One is timing and the other is putting the wrong cam in. They are both major screw ups but it happens. If you have the specs on the camshaft you can check it with a degree wheel and a dial indicator. This is called "degreeing the cam" and is generally done to squeeze the maximum horsepower out of an engine.  If this is your problem you would most definitely have to pull the pump off to set the timing. Did you mention in an earlier post that the compression was good? This would indicate the valve timing is acceptable.

 

 

 

Sounds to me like the advance mechanism inside the distributor is not advancing. (From what I read, this is a common Chrysler Marine problem.) The shaft tends to rust in place and/ or the little springs gag over time, which locks the advance in place. Can you put your light on the motor and blip the throttle to see if the mark advances properly (in comparison to a "good" engine).

 

 

 

Definitely sounds like the distributor advance. Did you find the correct timing mark? I suggest you get a dial back to zero timing light. They are not that expensive any more (1 hr labor) and it is the best way to check total advance. With one of these lights you only need to use the TDC mark and you just dial in 5 degrees or whatever your idle timing is. When you get the idle set you can then rev up the engine to about 2500 rpm and check the total advance. I am not sure of the Chrysler spec on the 318's but someone on the list will know. But if you are getting 20-25 degrees total the engine will run ok. The other way to check this is to place a mark on the harmonic balancer that is about 20-30 degrees advance and check to see that you are close.

 

I think if you want to solve this yourself without hiring an good (expensive) mechanic you will just have to go through each item and make sure it is meeting specifications.

 

 

 

Did the rebuild include new ignition wires? I had a similar problem that was due to old wires that didn't get enough juice to the plugs above 2,000 rpm. Test by spraying a little Windex on them while running at idle in the dark. If you see sparks, the wires are bad

 

 

 

Louder and hotter exhaust can mean late timing. This can be a stretched or jumped timing chain (valve timing) or at the distributor. You can check water flow by putting a bucket under the exhaust and use a stop watch to time how long it takes to fill. Do this for both sides and if you have a large difference then you need to work on the seawater cooling circuit. NOTE: Do not attempt this from the water - lower the bucket from overhead as being in the water or too close to the exhaust outlet can easily cause CO poisoning.

 

 

 

I will check the water flow rate at the exhaust for each engine and then look at the timing and distributor if water flow is not the problem. I hope it is a water pump problem.

 

 

 

Do yourself a HUGE favor and buy one of those digital temperature gages (with the laser beam locator--about $80). This fantastic tool should be in every inboard boat owner's tool kit! All you have to do, to find out what's happening, is start taking temperature readings on each manifold, starting at the front. Do the good engine first, to get a feel of what is correct, then do the 'loud one'. Make up a diagram of the motors and have an assistant jot down the temps as you go.  The problem should jump right out at you. I have a feeling one of your water passages in the exhaust manifold is clogged. That would account for the loud noise, and this is dangerous! Sure, you could rip the whole thing apart, to attempt to determine what's going on, but this way is a whole lot easier, right?

 

 

 

When I left the marina and the starboard engine was giving me trouble, so I had to change the fuel filter, alternator belt and spark plugs. That got the engine running great, but the port engine was smoking a little bit. A well meaning guy on the dock wanted to adjust the carburetor. He sounded like he knew what he was talking about, but after he worked on it for a while it became obvious that he was over his head. Finally get it going, get out of the marina on the way to the campsite the port engine cuts out, so I go across the lake with only the starboard engine. Get to campsite, and a friend who is an auto mechanic fixes the stuff that the guy on the dock messed up, by ear. Then the starter on the port engine locks up. It has done this before, and I would hit it a few times with a hammer and it would work, but now it is stuck tight and the hammer trick does not work. We take a boat ride with only the starboard engine running and make it 1/2 way to where we are going before it starts cutting out, so I have to turn around and head back. I think the fuel filter is plugged up again from crap in the tank.  The old girl is in the shop again, getting a new starter for the port engine. Also having the mechanic tune both the engines up, change the oil, put in two extra inline fuel filters (the kind that can be taken apart and cleaned) and other misc. things.

 

 

 

Here's a nice tech question for some of you who like to work on engines and know what you are talking about: My brother-in-law just bought a 1991 flybridge sedan. He just got the written report on its Chrysler 318 engines by the mechanic who handled that part of the survey. It says all cylinders had compression readings of 155 except 3 & 4 on the port engine, which were at 145, and 5 & 6 on the starboard engine, which were at 150. He asked me if this sounded about right for a 91 with 350 hours and I said I don't know - I have never had compression checked on my 89. I would guess those readings are about right and the small variance is not anything to worry about. But what do you guys think? (Excellent.)

 

 

 

 I have two marine power Marine Power engines that are carbureted with Vortec heads rated 315 hp. Yes she goes like stink! (The MPI engines were rated 325 hp.) The engines come with dual oil filters and dual accessory belts. The biggest problem I have with these engines is that I did not go to a 1.5:1 reduction transmission and 16" props. The 14" props cannot hold back the engines. We had to go through numerous configurations to get a decent performance. Although 14 x 12 with a heavy cup did yield 32 knots at 3700 rpm at WOT. This was acceptable to me but not the engine warranty. Also Fly Bridge sedans get pretty hairy over 30 knots. Just not enough boat left in the water. If I was starting over I would definitely go with 1:5 trans. I would take a hard look at putting a pair of fuel-injected 240hp Vortec V6's into the boat. With correct transmission and props and a couple of hundred pounds lighter boat this should out perform the original. Also should do better on fuel.

 

 

 

The throttle just above idle is quite delicate; just a slight push and the engine revs up by about 500 rpm and I have to tap it gradually down to where she'll run reliably and allow me to shift. If I tap down too much, she will probably stall. When the engine is really warmed up this all happens less, but it still happens. I can't bring the throttle back repeatedly to full idle without encountering a stall. No problem with the starboard engine. It'll start readily, idle and shift nicely, even without being fully warmed. First time this happened was last fall as I was winterizing. Kinda popped up suddenly after years of smooth running. It idled so poorly, the trans was rattling loudly and angrily. So this spring, I changed plugs, the in-line fuel filters, and distributor caps and had a mechanic time the engine. And, I assume, adjust the idle speed. He suggested I burn off last season's gasoline and use a fuel cleaner. Fuel is burned off now along with quite a few pints of carb/fuel cleaner. I have fuel/water separators and have emptied the small amount of crud regularly. The port engine doesn't have any more sediment than the well-behaving starboard. Incidentally, at speed, the engine seems fine with fuel usage even between the two. Any suggestions. Could the throttle control cable be the place to look, or an idle speed adjustment? I would consider disconnecting the throttle cable at the carburetor body and try (at dockside) working the throttle from on the carburetor, and see how it works. (Sounds like a flooding carb problem.)

 

 

 

I am not an engine expert, but too I have sticky throttle cables...FYI, a 37 ft aft cabin w/ 5 ft factory cockpit, Chrysler 330 hp engines. When you are dealing with these older engines as most of us are, there is a laundry list of tune up issues that can affect this. I went through a similar set of problems a few years ago and it was starting to take all the fun out of running the boat, especially backing in between pilings. The problems got gradually worse over a few months and I was trying all the popular fixes, Carb adjusting, carb cleaner, ignition tune up, vacuum leak testing, etc. I know a very good mechanic that felt it was inside the carbs, (Rochester Quadra jets), I had them rebuilt by a pro and for the last 7 years my Chryslers have run up and down the rpm range like electric motors on rheostats. The rebuilder said there was a lot of white oxide in the carbs and some passage clogging. The cost was $190 for the pair back then, up till then I had spent almost that much getting opinions from some guys that really didn't know squat. I think your port carb simply needs a good quality rebuild. The problem is the intermediate circuits of Carter AFB carbs; they tend to clog easily and are resistive to cleaning. I soaked mine in carb cleaner for several days and the damn thing still has a bog.

 

 

 

One thing one can do to correct that bogging situation is increase the accelerator pump shot. Here's how this is done: An arm at the top of the carb pivots to work the accelerator pump system. One end of the arm pushes down on the accelerator pump, the other end has a rod that's attached to the rotating throttle assembly. There's three holes in this arm, for adjustment. With needle nose pliers, carefully remove the SOB clip (hair spring) that keeps the rod from falling out. Next, move the rod to the closest hole to the pivot, then re-insert the SOB clip. That will help until you get her rebuilt.

 

Good luck! And if you lose the SOB clip (which is easy to do) a good auto parts store or hardware store has them. I keep several in stock on my boat.

 

 

 

I am just now near completion of major external engine overhauls on twin M360's in my '76 Trojan F32. Prior to rework, engines would steadily overheat above 3000 rpm.  Besides replacing the impeller and all hoses, I also removed and reworked all exhaust components. The risers and elbows were completely cleaned via electrolysis. The elbows were both about 90% blocked, the risers about 30%. Both are now clean and wide open. The cleaning was done at home with 5 gallon buckets, a battery charger, anodes from rebar tie wire (not rebar) and caustic soda and washing soda as an electrolyte. Another benefit is that the electrolysis loosens rusted bolts to the point they come out easily with pliers.  Both elbows were cracked at the outlet, so I brazed the cracks and ground the joints clean. As best I know, the risers and elbows date back to 1986 when both engines were rebuilt by the previous owner. I see no reason I will not be able to get another ten years out of them.

 

 

 

Leaving for two weeks on the boat (37 aft cabin, twin 440 Chryslers) this Saturday, and wouldn't you know it, I try last night to start the engines (just to make sure they start) and the STBD engine won't turn over. If I use the parallel switch, it starts fine. Worked fine all summer up to now.

 

I am not certain of how my batteries (3) are arranged--haven't had to worry about it until now. I have two batteries behind the STBD engine and one battery behind the PORT engine. For this discussion, we can ignore the port battery. I disconnected the outboard battery behind the STBD engine--completely--NO wires connected to it. Had my wife try the STBD engine, and it turned over normally. So, obviously, the battery I disconnected is not the STBD starting battery. However, when it is connected, I cannot start the STBD engine without using the battery-paralleling switch. Immediately after re-connecting the previously disconnected battery, I flipped the starter toggle and the STBD engine turned over. I flipped the switch of then on again; nothing, except some buzzing from under the black cover with red reset switches on it that is mounted on the engine (don't know what it is called). No way to turn over the STBD engine without using the parallel switch.

 

I am wishing I had my wife try several times with the aforementioned battery disconnected to see what happened with multiple attempts, but we were rushed for time and had to get home, so now I have all night to ponder this problem. I realize it can be hard to troubleshoot with information I have given you--especially without knowing the battery bank arrangement--but I need suggestions and a direction to proceed. Batteries were (so I am told by previous owner) brand new last season. Oh, water does cover the plates in all the batteries. Also, I put a multi-meter on the battery I disconnected when it was disconnected, and it read 13.56 VDC. (One of the three batteries is a dud.)

 

 

 

HAVING PERFORMANCE PROBLEMS?

 

 

 

If you're sure the 16 x 15 is the correct prop, then the drives are probably 1.5:1 instead of direct drive (1:1 ratio). The serial plate on the drive will have the ratio stamped on it. You say when you did the sea trial both engines peaked out at 3,700 rpm, but went down in speed as the trip went on. When the rpm's started dropping did you get any type of odor from the engines? Like a burning smell? If you did, it may be that the 8 degree wedge plates under the carbs are missing. If the Rochester is like the Carter, it needs to be as level as possible (especially at WOT). If the carb is not level will starve the engine of all the fuel it needs to produce the horsepower that is needed to reach its maximum rpm. This is what is called (in NASCAR terms) "leaning out". When an engine runs too lean it causes extreme heat in heads and intake area of the engine. And when I say extreme, I mean hot, hot. Hot enough to cook a 16 oz. T-bone well done in under a minute. And, here comes the worst part. Even though the top of you engine is frying, none of your gauges will give you a clue. This is not something I have read in a book. I'm telling you this from having experienced it first hand on my own boat. I have a 1964 26' Marinette I've had for 25 years now. The original 327 Gray was replaced with new 1968 318 225 hp crate engine and drive package. The swap out was done by a certified Chrysler Inboard Service Center. No shade treeing involved. I buy the boat 2 years later and after little fix-up paint-up off we go. The engine runs as smooth as silk. The only thing I found bad on the engine was the old Carter AFB carb the dealer had installed not as new as the rest of the engine. It idled good and ran ok up to the point where the back two barrels came in. When they opened the boat just laid down. When I tore the carb apart to clean and rebuild it, I found that the back half of the old AFB had passed the rebuildable point about 30 years ago. And since I didn't have an extra $500.00 laying around for a new one, I cleaned and rebuilt as much as I could and put it back on. I didn't need those extra 2 barrels anyway--I have been through the ‘go fast’ stage of my life. One reason I bought the old boat was to be able to cruise around slow and relax a little. I ran that old AFB for 10 years without a problem. After pulling her out and spending a few years restoring the old girl, including rebuilding the engine, the old AFB was still alive (well, half alive anyway). I ran it for a year before making the plunge to buy a new Edlebrock who manufacturing a direct replacement carb for the old AFB. It was only $360.00. It was a perfect fit, except for the flame arrestor. The new carb is 5" and the old one was only 4". And boy, did it run sweet! Couldn't wait to try it out. It would be the first time out with all 4 barrels working. I had never given a thought to how fast it would go or how many rpm's it would turn. The sound when the back barrels came in was awesome. I didn't have a GPS to tell the speed but she topped out at 3500 rpm. I had never checked to see what it was supposed to turn. Right then, I really didn't care. I could barely get to 2,400 before. It felt so good that I held it at WOT for about 2 minutes before backing it down. When I dropped back to about 1,500 rpm there was an odor that smelled like the engine was overheated. I checked my gauges and they normal. When I brought it back to idle, the engine sounded terrible. It was running real rough and the valve lifters were pecking. I shut it down and raised the engine hatch to see what was going on. The engine looked and smelled like it was about to melt. It was so hot that it was making the sound a hot car muffler makes as it's cooling after you shut the engine off. I had been an auto mechanic all my life and had never seen anything like this. How could this engine be so hot and the temp gauge reads 160 degrees? I let it cool for about 15 minutes before trying to start it. It fired right up and the lifters peck a little at first, but quieted down right away. I eased back to my slip and parked it, still baffled by it.  To get to my point on this, after spending many hours trying to what could cause this problem, I finally stumbled across it on the internet. I printed it out and I've got somewhere, but I can't find it right now. The engine in a straight inboard (direct drive) application must be installed at a pretty good angle in order be aligned to the prop shaft. At such an angle the carb will not distribute fuel properly. To solve this problem the intakes used on inboards are made with an angle where the carb mounts so it is level. That makes sense and the intake on my engine had the angle as it should. Then I see the "Note:" at the bottom that says if the engine is installed at more than a certain degree, (as the Marinettes are) that a wedge plate must be added under the carb. Why the hell didn't a Certified Chrysler Dealer know this?

 

 

 

I purchased a wedge plate for $46 and installed it, and guess what? Not only did it cure the lean burn problem, the engine rpm went to 4,200 just like the specs say it should. Check to see if the plates are installed under your carbs. If they're not, you need to get some. If they are installed, I can't think of anything else that would cause it.

 

 

 

Nine yrs ago, I burned out several forward cylinders in both engines at the same time. Holes the size of half-dollars.  Both engines were history, replaced by Jasper rebuilds.  One of the leading explanations at that time was that, for some reason, cooling wasn't reaching the forward part of the engine, and running only briefly at WOT they cooked.  There was never a definitive explanation.   The carbs were (and still are) Rochester QuadraJjets and I haven't the slight idea whether they are equipped with shims.  But to this day, I always say a little prayer when I have to run at high speeds even for a half a minute. So far, so good.

 

 

 

SOME TYPICAL Q & A:

 

 

 

."Do I have the advance springs on the electronic ignition?"

 

Yes!  The only setups that don't use mechanical advance are computerized engines.

 

 

 

If your motors are not working hard at cruise speed, there's no reason for concern if they don't hit 4,400 rpms at WOT.  Many Marinette owners report that their engines don't exceed 4,000 rpms at WOT.

 

 

 

“My engines burned holes in the tops of the pistons. Was that caused from lack of coolant?

 

 

 

Possibly, but more likely it was caused by "lean burning".  If you are a NASCAR fan, it's the same thing that was happening to their engines when they started having to use restrictor plates at Daytona & Talladega. They were burning holes in the pistons because the restrictor plates changed the fuel/air mixture and if they were too lean it would burn holes in the pistons. They've figured out how to get the mixture right now, but it gave them fits for a while.

 

 

 

I cracked open the distributors last night. Both had new caps and rotors, so never gave them much thought. Both distributors look rusty brown inside. Is that normal? (Unfortunately yes.) How can I tell if there are any problems in there? Where do the springs go? (Under the plate.) How do I check them and/or replace them? (Must pull the entire thing apart.) How rusty brown?  (Typical rusty brown.) 

 

 

 

Here’s an easy distributor test: Turn the rotor with your fingers against the springs.  If it moves about 20 degrees--then snaps right back--it may be okay.  The best way to tell the advance is working is to use a computerized timing light: rev it to 3,000 rpms and read the total advance. If you don't see at least 25 degrees, and it's initial advance is timed correctly, then the advance is not working right.

 

 

 

ON THE CHRYSLER TIMING POINTER AT THE FLYWHEEL:

 

 

 

Zero degrees is at the point of the 'arrow' on flywheel timing setups.  The 5 degrees initial advance is on the side of the 'arrow' (for standard or reverse rotation). The weights and springs are under the plate and star shaped reluctor.  The reluctor is supposed to be removable but both of mine were rusted in place.  If you remove the felt oil pad in the center of the shaft there is a small circular spring clip that can be removed with a narrow screw driver or needle nose pliers. Then the plate/reluctor assembly can be removed to expose the weights underneath.  One spring is heavier than the other.  The heavier one tends to rust solid preventing it from extending. Don't forget to replace the circular spring clip and felt pad.  My advice after messing with a few of these distributors is, DON'T take it apart unless it's shot. The way you are supposed to reassemble the thing starts with the reluctor wheel removed, but they do not easily come apart.  You CAN get the plate back together with the wheel on the shaft, but it's very hard to do.

 

 

 

I agree that having the alarm ON while cranking the engines would make it difficult to hear when they crank.  Besides, it is such an irritating sound I would not want it to be sounding while cranking even if I could hear the engines over it. My thinking is as follows (and I admit that I haven't fully investigated the configurations available). Right now, from the FB and below, my ignition switch is a toggle that it is fully OFF when down; the starter is engaged when the toggle is fully up, and the engine is active when in the center (RUN) position. I have an extra switch that I need to remember to turn on after the engine is running to enable the engine alarm. My thought is to go from what I generally think of as a separate Alarm Enable switch to a single ignition switch that allows me to integrate the alarm into it such that the alarm is "enabled" only when the ignition switch is in the "run" position" I'd probably need to get more of a traditional ignition switch (probably keyed but that is not something I'd necessarily want) where 2 "poles" of the switch operate the same as my existing ignition switch and a third "pole" enables the engine alarm only when the switch is in the RUN position.  Basically, engine ignition and alarm would be connected to the RUN tab, and ignition and starter would be connected to the START tab. Each engine would have it's own alarm buzzer and light AND I would get buzzers loud enough to hear them even when the engines are running at high rpms (not sure if the existing one is that loud).  When starting, moving the switch from OFF thru RUN on the way to START would cause the buzzer to sound for an instant as it passes RUN with the engine not yet running (to give an indication the buzzer is working).  While the switch is in the START position, the alarm would be off (disabled).  When in the center (RUN) position, the alarm would be enabled to sound for any conditions that now cause an alarm (assuming I remember to turn on the switch).

 

 

 

The reason I'd probably need a traditional ignition switch rather than just a double pole toggle switch is because I've never seen an OFF/Center ON/Momentary_ON toggle switch.  The ones I've seen are ON/Center OFF/Momentary_ON.

 

 

 

An alternative to the above could be to have a "master" panel enable switch and basically never "disable" the alarm switch but not turn on the "master" switch until after the engines are running.  I would not forget the "master" because I always remember to turn on the depth sounder (right now I do it before cranking the engines) or would notice quickly if it was off.  Of course, I sometimes want one or more the panel switches to be enabled with the engines off which would cause me to "disable" the alarms and I'd need to remember to re-enable them. Anyway, that is what has been going through my head on this.

 

 

 

ON WEIRD PROBLEMS AND SOLUTIONS:

 

 

 

How would a water restriction cause LOW temp?  Especially when the engine block is not hot to the touch (I think I'd understand a restriction causing low temp reading but the engine got hot to touch.)  It seems to me that since water cools the engine that less water would raise the temp and more would lower the temp. My starboard engine (the one that I did not rebuild) runs cooler than the other.  The port engine gets to 140 very quickly but the starboard sits at around 120 until I start running out a bit then goes to 140 pretty readily.  When they rebuilt the port engine they told me that they needed to work to remove mud/silt from the cooling channels in the motor so apparently the boat was run a good bit in silty/ muddy waters before I got her.  My working assumption is that the starboard engine probably has the same mud/silt inside it.  Note that even pre-rebuild, the port engine ran warmer than the starboard if memory serves me correctly.  Another thing I was told by the rebuilder is that at some time the port engine had gotten too hot. Assuming the starboard engine does have mud/silt in the cooling channels, is there a way to get it out without rebuilding? In case it matters, my engines are Crusader 454s.  (A major flushing operation, perhaps, with a hose shooting water in and the drain plugs removed?)

 

 

 

I was talking about those weird, dual pocket pump, old Chryslers. There was no circulating pump on the motor, for they using the impeller in the Sherwood pump instead.  Since that's a positive pressure pump, the only way you can reduce water flow thru the block (during warm up) is to restrict its flow. Water will squirt violently past this restriction until the t-stat opens, after which flowing thru the block becomes 'easier'. Water then takes the easier path.

 

 

 

Generally the industry recommends inspecting exhaust elbows and risers and all exhaust hoses and fittings annually. They say that in salt water one could expect aprox. 5 years life for an exhaust elbow, and longer if cast iron, but no more than 10 years. Fresh water would be longer depending on water quality.

 

On the subject of WOT running I'm not a motorhead but I'll make a couple of observations and offer an opinion which is worth every bit of what you paid for it.  In the 60's we had a couple or 3 Marinettes and would run them at near WOT when we were water skiing.  We did that frequently and would run 30 minutes or so at a time.  We probably put 300-400 hours a year on the engines (remember that gas then was $0.25/gal).  Never had a problem with blowing an engine but these Marinettes were bought new so new engines.  Also, it is fairly normal to run I/O runabouts at or near WOT for extended periods.  Sure ... you can go too far ... but I've been told by some that should know that motors like we have in our boats like to run hard sometimes. 

 

Our engines should be able to run at higher rpms than they are propped for, so I'd guess we probably aren't pushing them overly hard at WOT.

 

Having said the above, I also realized that many of our engines are "old men".  I recently had my port engine completely rebuilt so it should be "like new" again but my starboard engine is probably 22 years old with who knows how many hours.  So, even if I had no problem with the gas, I probably would not run at WOT longer than 10 - 15 minutes at a time and not all that often (I occasionally do 5-10 minutes now).  I do try to take her up to near WOT for at least a few minutes every 10-20 engine hours to blow the deposits out (again, a recommendation from somebody who should know).  I have decided that I would like to go ahead and have my starboard engine rebuilt sometime.  If I do that, I would feel relatively comfortable pulling a skier for about 30 minutes but I wouldn't do that often because of the cost of gas and the irresponsibility that would be for the environment. So, if your engines were rebuilt or replaced in '98, I'd think you wouldn't have all that much to worry about so long as you are reasonably meticulous about your routine maintenance.

 

 

 

I had the same problem with my 39' DC. I went through my carbs last year and still could not get above 18-19 mph. Then last week I noticed my starboard engine would speed up from 1,800 to 1,900 rpm if I pulled the WOT back a little. I went through the star carb one more time and found a bit of blockage (not totally blocked) in one of the small galleries (fuel circuits) of the right-side secondary end of the carb. (I used a bore-light to find the blockage.) I now run 32.4 mph with a 3800-3900 rpm on both engines. First time since owning the boat for 4 years. Point: find out which engine is lagging, and perform a very methodical inspection on the root problem and don't rely fully on the experts that over look small things that caused.

 

 

 

 Took the boat out yesterday for 1.5 to 2 hrs and ran several miles on plane, then throttled down and ran the rest of the time around 1,300 rpm. Engines ran fine the entire time until I got back into the harbor. First the starboard engine shook and then quit. A minute later the port engine shook and then quit. Was able to restart both of them almost immediately but they kept dying, each time shaking quite a bit right before they died. Just barely managed to get her docked. Fooled with the engines some more at the dock. They'd idle for a few minutes and die. Would run smooth at idle.  Able to run at various rpm's up to 5,000 and would run smooth. The only odd thing was that the engine would shake for a second or two as I advanced from idle to higher rpm but then ran smooth at higher rpm. Both engines had the same behavior. I was convinced I had water in the gas, so I went back to the boat today and drained both Perkos. No water at all, not one drop, and both looked very clean. Reassembled the Perkos and ran both engines at idle for nearly 20 minutes, both in and out of gear and they both ran flawlessly.

 

 

 

The following opinion is just that and not based on fact - just a hunch.  My Perkos came out bone dry this spring and early summer.  By that, I mean there was not a drop of water or crud in them after a long winter.  Others have had a similar experience. I cannot believe that after years of pulling some quantity of water and dirt out with the (now) former Perkos.

 

So, I think that somehow, the water binds to ethanol and slips past the filters, along with dirt and that is causing problems. Including your problem.  I have not checked my filters in recent weeks but will do so soon and will report back. 

 

 

 

FROM SOME DOPEY DISTRIBUTOR MANUFACTURER:

 

 

 

The primary exception to this is with engines such as some Chrysler based marine engines where the distributor gear isn’t on the distributor. The drive gear is mounted on a separate shaft that drives both the distributor and the oil pump. In those engines, the exact same distributor fits both standard and opposite rotation engines because the gear on the separate shaft is matched to the camshaft’s drive gear." 

 

 

 

Manure!  The reverse rotation distributor in 360s (and probably 318s as well) is VERY different:  It has a special thrust bearing to counter the opposite rotation thrust load and a bushing in the manifold.  In other words, the port distributor will not even fit in the starboard engine. The interesting thing is that I called Mallory and several other companies and they did not even know the distributor would not fit. There is a spacer in the RR motor to lift the distributor high enough so it fits. The damn hole the distributor has to fit into in that motor is to small for any of the new distributors. (there is a sleeve installed to do the lift) I had to machine both the sleeve and the distributor to make them fit. After that it worked ok. But you need to add in another $100 to the cost and get a good machinist.

 

 

 

Were you installing a Mallory distributor? If so, was it for marine or auto? The reason I'm asking is Mallory knows there is a difference. And that difference is the reverse rotation engines. The distributors in all 318/ 360 Chrysler engines rotate in the same direction, be it right or left hand. In a boat with twin 318 engines, one is RR and one is LR. The distributor rotation however, is the same on both engines. And because the gear that drives the distributor on the Chrysler engines is not installed on the distributor shaft, there is no difference in the distributors themselves. But there is a difference where the distributor fits into the engine. If you buy a Mallory Marine Application distributor (Mallory part # YLU579AV for the small block 273-360) it will come with the spacer needed to install it in a reverse rotation engine. How I know this? Because the single 318 in my boat is a CC W. rotation (when viewed from the front) and needs the spacer. The spacer is black and made of plastic, and worked perfectly.  A little more info for everyone: Summit Racing is the one that lists the Mallory Marine Distributor. Summit's part #MAA-YLU579AV. The same as the Mallory # with MAA in front. I could not find a Mallory Unilite Marine listing at Jegs. Their part # for the mechanical advance Unilite for the small block Chrysler is 650-3757901. The price is $64 less, but if it doesn't come with the spacer, it's not worth it. Hope this helps someone.

 

 

 

ON OIL LEAKS:

 

 

 

My ~@(@%$# valve cover bolts were loose, causing an oil leak. The oil pan bolts were tight at least the ones I could get to.

I had some concerns about not using a torque wrench on the bolts so I just snugged them down. (Smart move, for the most dangerous tool in a mechanic’s toolbox is a torque wrench.)

 

MORE ON ENGINE PROBLEMS:

 


I think age rather then use is taking the toll on our engines. I don't think the average boater can wear out his engines when you compare usage and hour accumulation to a vehicle engine. On the other hand my car engine does not pull 11,000+lbs of weight through a resistance. The engines on the project 32' got a good test today. This is the boat that sat at a marina for years.  The port ran good and the starboard ran even better.  The engine hour clock now has 83 hours.  I hired a professional boat guy to help me.  We ran it on the hard with a hose and a outboard tank after I put in new impellers and belts.  The conclusion is the engines are ready to run in the water.  The temp gauge on the port side jumps around a little.  The starboard stays steady on 160.  The professional says to put a new t-stat in the port.  Also, I will burn all that old gas in my truck not in the boat. Today's update: got mechanic aboard to re-look at carb and related items like stalling after a run.  He was supposed to have been there two weeks ago. We ran engines a little and noted that vacuum oat idle on the port engine is only 15 or 16 (inches). Stbd is normal.  He says that could indicate improper timing (retarded).

 

 

 

So, what about vacuum readings? I was advised to have the mechanic look at the idle circuit. Another suggestion was to turn the idle screws all the way in. The engine should starve for fuel and stall. If they don't, the idle is off and the engine is probably flooding. Which could account for the port side greater use of fuel by upwards of 15%.

 

 

 

My friend used my boat last weekend and told me that the stbd engine wouldn't get above 3,200 rpm without missing and nearly stalling.

 

We went out there tonight to debug and the first thing I noticed was that the port fuel tank was considerably lower than the stbd tank.  They were about equal the week before--I pay attention. Went right for the fuel filter/ separators and dumped them (again) into clear jars.  No surprised here: a difference in color and much more crap in the stbd filter. Reused filters (didn't have spares yet) and took out for a run - Both engines right up to 4,200 rpm with no issues.

 

 

 

ON TWIN MOTORS NOT TACHING OUT THE SAME:

 

 

 

 My theory is that the port engine has to work harder to run the boat.  I'm not sure on the sync.  My guess is the throttle linkage is way off.  They are right on now that the engines are running again.  Other than check the dist caps real quick, I went right for the stupid stuff.  Dump those filters and see what you have.  Be sure to dump both sides and compare them.

 

 

 

HOW IGNITION POINTS WORK:

 

 

 

When the points close, the current in the coil primary starts to ramp up, as energy is stored in the magnetic field within the coil. When the points open, the magnetic field collapses and, since there is no circuit on the primary side when the points are open, the collapsing field induces voltage in the secondary circuit. There are many more turns of finer wire in the secondary, which helps the voltage output build up until the air between the spark plug electrodes ionizes. Then the energy from the collapsing field dissipates by driving current through the plug, setting off the mixture in the cylinder.

 

In a perfect coil, the current will continue to ramp up without limit. A real coil has some resistance in the wire that limits the current, but to a high value. When the engine is operating at speed, the points open in plenty of time to prevent this high current, but when the engine is stopped with the ignition on and the points closed, this high current will burn out the coil.

 

So, there is a resistor in series with the coil primary that limits the primary current. This has the advantage that much of the heat generated by the current is NOT in the coil, but in the ballast resistor. When I was young my friends would short out the ballast resistor with a switch to get better top-end performance. Or they thought they did. But forgetting to open the switch before stopping can fry the coil. Of course, many engines do not use a ballast resistor, such as those with a 12 volt coil.

 

 

 

ON FLUCTUATING ENGINE TEMPERATURES:

 

 

 

It may be erratic thermostats. I contacted Teleflex and they suggested the thermostats might be opening and closing. The movement is smooth up to around 180 then back to normal. Electrical gremlins would have the needles peg or jump wildly. I had replaced both thermostats this fall at layup. They’re the only thing really common to both engines.  I now have put one of the old thermostats back in the STB engine and the gauge is working properly. Waiting to see if Port engine gauge acts up. If it does...that will confirm that it is defective stats.  The duration of the change was too short to effect engine temps.  The stats opened then closed for a few seconds. (Not enough time for the heat to transfer to manifolds, etc.) Looks like NAPA sold me some cheap stats.  By the way... the folks at Teleflex responded within hours of my E-mail. Great folks to work with!  If it was not for them I would have continued to search for electrical faults. Hopefully this is the end of the malfunction.

 

 

 

ON DISTRIBUTORS AGAIN:

 

 

 

Mine was replaced on my port engine during the rebuild at a cost of about $150. It required replacing coil and all wires too because it used higher voltage.  When my weights stuck on the starboard engine I decided I'd rather have the same on both so didn't try to rebuild.  Mine are Crusader 350 hp. I don't know. I'm not good w/ motors but if I had to guess I'd say that the distributor is the least likely culprit of the items I replaced - when those weights stuck the engine operation went to heck in a hand basket. Again, I'll let others correct me but if the hotter plugs fix the problem I think I'd use that as a clue to track the real problem rather than accept it as a solution.  I did accept it as a solution on mine but after I redid the carb/dist/fuel pump I heard that hotter plugs could do damage. I have heard, especially with the lower thermostats used in RWC engines, that heat exchanger hot water heaters don't get as hot when using the engines as when using the 120Vac heat.  I haven't measured it but I'd be very surprised if my hot water is not above 140 degrees (engine thermostat rating).  (My heaters are 120Vac only.)  I haven't done this after a hard run but I have felt the water coming out of my exhaust ports after the engines were registering 140 degrees and that water is not nearly as hot as my hot tap water.

 

 

 

Note: With raw water cooled motors, the water should not get over 150 degrees.  The manifolds run 10 to 15 degrees cooler than that, so I doubt if one could get scalded. One strong word of caution:  The coolant back pressure in a raw water cooled motor is very low--about 1 psig at idle, and about 6 psi at high rpm. That's not a lot of pressure to push water forward and uphill through small pipes/ hoses to a heater, and back. And if it won't move fast enough, that water will heat up!  Not good if it's supposed to be cooling the motor and exhaust system.

 

 

 

MORE STARTER PROBLEMS:

 

 

 

Check the connection to the starter itself.  I replaced a solenoid but later found that the terminal bolt on the starter was corroded and gummed up. 

 

On the neutral safety switch, one day as storm clouds gathered my father-in-law and I tried everything to get the 318's on our Trojan F-32 started.  After about an hour I finally figured it out.  My son had been pretending to drive the boat while we were on the hook.  He bumped the shifters just enough to disengage the switch.  I've not had the opportunity to look at the wiring beneath the shifter yet. I'm feeling the starter/bendix is ok.  I scratching my chin on the shifter though, because the coil is getting really warm when I try to start it.  (Note: The coil has nothing to do with the starter interlock system.) A visual inspection revealed no corrosion on the starter connection.  Frankly, I don't recall if I gave them the wiggle test after the hammer-to-the-starter test.  But I will... and if that's it, I will be soo embarrassed!

 

 

 

MISCELLANEOUS:

 

 

 

If Borg Warner is making now making transmissions that handle counter rotation (they are) then it makes sense to stick with two standard rotation engines.  My velvet drive 1:1.5 reduction gear reverses the input rotation and can be adapted to handle left or right rotation, but the input rotation is only determined by the engine.  New trannies cost thousands.  So do new marine engines.   

 

 

 

What do you mean small block Chevy?  You mean a marinized small block like a GM Vortec 5700 not a car engine?  (It’s a Chevy engine!) 

 

 

 

Somewhere during 1987 Chrysler improved the oil setup on the engines. My 1986, 360 have the dipstick going into the block, not the pan and have no garden hose fitting. To change the oil I unscrew the dipstick from the block and sneak a little stiff hose down into the corner of the sump and use a small impeller pump to suck the oil out. Works well. My 1989, 318 Chrysler's had the garden hose fitting w/ the stick at the bottom of the pan. I think this change came along w/ the use of center dump manifolds.

 

A BUNCH OF CARB QUESTIONS:

 


I've been chasing the same problem on the starboard engine (1979 Chrysler 318) for several months, including stalling when docking and stalling when powering up from idle. Started with the electrical system: new MSD wires, new coil, new plugs, new module. Cleaned the flame arrestor then replaced it with a K&N arrestor. Ran better, but still had the problem. Frustrating aspect was that it was unpredictable - some days were great, some days I wasn't sure I'd make it back on both engines. Last week, replaced original carb with new Edelbrock 1409, new fuel pump, new fuel lines, new fuel filters. Went ahead and did both engines. Boat now runs great! Dave's problem was that his old Carter AFBs were random slow flooding, a problem with those old clunkers. 

 

 

 

“Can I use Edelbrock carbs on mine?”

 

 

 

No. Your boat has Rochester Q-Jets, which have an entirely different bolt pattern and holes in the manifold.  The only carbs that fit are marine Holleys of the 'spread bore' type.  Frankly, the "Rotten-Chester" is about as good.

 

 

 

Any problems adapting the Edelbrock’s throttle linkage? 

 

 

 

No, and I didn't even break a sweat wiring up the electric choke!

 

 

 

On those overlooked but critically important temperature switches:

 

 

 

ON THE ENGINE ALARM SYSTEM:

 

 

 

I didn't realize that there are already temperature switches in the exhaust with the gas engines.  The only problem I see with them is testing them. Like the coolant overtemp switch, the only way to test them is to take them out, put them in boiling water, and see if the contacts close. This requires removing a few gallons of coolant, so I only did it once. All of my original engine wiring is gone, but I have an "engine alarm" breaker on the eyebrow panel that I assume is the switch to which you refer.  I don't use it.  I have each engine's alarm circuit wired to its 'ignition'. The alarm sounds when the key is turned, and continues until the oil pressure comes up. If someone turns off the key, the alarm is gone, but the engines go right on perking. This is not good, but I haven't thought of a cure.

 

 

 

The normal Chrysler engine alarm setup has a temperature switch in the intake manifold (besides a temperature sender unit for the gage) and one or two switches in the risers. These are switches, not sensors, and they close to ring the alarm at around 200 ‘ F.

 

 

 

That exhaust elbow alarm will not work the same as an exhaust alarm. The exhaust alarm needs to be in the exhaust flow after mixing, not in the water jacket. In the exhaust elbow it won't react quickly to a water flow loss. First the inner elbow will heat up and then the air, which then needs to circulate and then the alarm will go off. You want the exhaust gases blowing directly on the temp alarm. I wired my alarms up to the start/run switch. If the switch is on the alarm gets power. To prevent back feed put a diode between the switch and the alarm (Dual stations). That way if your engines are running the alarm will be enabled.