I'm posting this here because I didn't see a category that seemed to deal mostly with engine stuff.

Some may remember a while back I was having a problem with one of my engines stalling at speeds above an idle after running fine for about 30 minutes. The 30-minute "timer" was very consistant and it did not seem to matter if we were in choppy or dead calm conditions and the engine speed until the problem started also didn't seem to matter. I tracked it to the fuel tank by alternately switching both engines from one tank to the other. Many thanks to all who offered suggestions - all were beneficial and many were very helpful. I thought I'd relay the results because I was off the site for a while.

I ended up draining the fuel tank - used an electric fuel pump to pump it out through the fuel input connection. I took about 35 gallons of fuel out (fuel bought at $4/gal - sigh) and 2 of the 7 five gallon cans contained something that looked and smelled more or less like gas (to me) but would not burn even if you put it in a fire. It may be "evil-nol" but my research indicated that it may have the byproduct of mixing gas that contained MTBF with gas containing ethanol - mixing the 2 causes a "gunk" and it will not burn. Since few of us actually let our tanks run dry, it is likely that there was a good bit of MTBF fuel in the tank when the switch to ethanol occurred - and to call it a switch is probably kind - more likely it was MTBF/ethanol/MTBF/....... Anyway, whatever the case there was a layer of bad stuff in my tank.

BUT! After draining and cleaning fuel filters the best I knew how and adding fresh gas, I still had the problem - about as bad as before.

At that point, I really dug into the stock Perko fuel-water seperators that come standard on the '84 Marinettes - the ones that look a bit like upside down bells - they don't make them any more by the way. After messing with them a while I found another connection I could take apart and found this "filter" (I presume that is what it is) that appeared to be a piece of semi-pourous wood. It didn't appear to be clogged or dirty but I proceeded to wirebrush scrub it and forced air through it and reassembled everything and it has worked ever since like a charm.

My guess is that the "gunk" in my tanks probably floated on the real gas and it was only the little bits that mixed during jostling that made its way into the filter and engine and that an accumulation on the filters (mentioned above) eventually caused a problem. If I had let the tanks get low enough, there may have been a more serious issue with the gunk getting to the engine but the filters may have stopped that too.

I have not done so yet but I do plan to drain the other tank and won't let it get very low before then. I also plan to replace my filters with Racor filters with replaceable cartridges.

I got two Marinettes. On my project 28' single I had the yard guy replace the old perko with a cartridge type because the threads were frozen and I couldn't open it to check the filter element. I also put a canister filter before the carburator because the little screen on the carburator was missing. The trouble is instead of a nice neat mostly metal fuel lines I got a chopped up mess of rubber, hose clamps and metal. I did put a see through canister filter on but the yard guy said it was not marine so I took it off. I would like to find a legal see through filter before the carb if I can find one. The project 32' had real old gas which I removed. It was clean enough just old. I am going to stick with the perkos and little carburator screen on that boat as long as I can. The first step when you get these old boats is to siphon out the old gas. You can treat it with a conditioner like seafoam and burn it in your old truck. If the last can has gunk or water, pour the first few cans back in to dilute the residue and siphon it out again.

Hi Joel,

Sorry to hear about the NAVMAN problem - I was interested in that system. So where did you find the ceramic Perko elements? I looked everywhere. I did eventually find a couple on EBay but was leery about them because they were not new. I don't have a problem with the Perko filters - I just want to replace the element. I do frequently drain the "water" but to be perfectly honest I have never gotten a drop of H2O - just a little crud (very little) in some gas. I didn't know about the ceramic parts because I had to remove the whole network from the boat to be able to see that extra connection where the element resides - just the where they're mounted in the engine room - limited access and view.

I also have not experienced the evils Jeff talks about but the mixing of the old style with the new did apparently create some pretty nasty stuff.

New Perko fuel filter elements can be purchased from Marinepartssource.com. The part number is PER0324001ELM (0324001ELM).


Rob

I switched back to the old style perko filters from the screw on type & it is amazing how much trash it catches. Wayne

My 2 cents on the Racor versus the old Perkos: I switched to the Racors about 7 years ago. I always carry two spares, but have never had a fuel issue since installing them. Every Spring I use those to replace last year's pair and put a couple new ones in my inventory.

The canister types are painless, use an oil filter wrench which we already have on our boats and there's no cleaning or air blasting involved. As I mentioned in a post a couple weeks ago, when changing filters for this season, the little filter baskets in my Rochesters were as clean as new, so the canisters are doing their job and an annual change-out is pretty cheap insurance.