Marinette Boat Forum

Is the white smoke while you are cruising? If so, that’s steam from the cooling system which is normal. If it happens when you first crank, that’s a valve seal leak I would assume. No big deal.

Mark your flywheel timing mark with a white metal marker. Makes timing way easier.

Tune your carb idle screws to max vacuum as mentioned. For vacuum tap I used a threaded plug that was located right on top of the intake manifold made just for that reason. Located about 5” fwd or aft of the carb. Seemed like it’s a weird size drive to get it out. I had to grind down a 3/8 drive extension to fit it. That vacuum gauge has many uses. It can diagnose many engine problems.

Keep us updated buddy.

.5 gap on plugs

Todd, I've noticed a similar scenario happening on my port engine recently. I can accelerate and push the throttle forward to 2500, and then it just seems to 'lag'. So, my "wall" is 2500... Although, most times I can "push it through" and then that PORT engine sort of catches up a bit... I can eventually get that engine up to about 3250 RPM max... that is enough power (cruise at about 25 knots in my 28') for me, but the port is not quite like my STB engine, which approaches 4000. The port is definitely in need of some kind of adjustment. I'm just curious if the phenomenon you experienced was similar to mine. I've experienced this over the past few seasons, but it seems to be happening a bit more as of late.

Thanks
Joe

Sounds to me that Mr STB might be off on timing, due to a stuck ignition advance. Have you looked at it with a light?

Jeff

Another thing that comes to mind is the little (CG-11) fuel filter at the mouth of the carb fuel intake. Just a possibility. Usually when that thing needs to be replaced you can't get more than 1,800-2,000 rpm but once in a while you can push through. It's an easy thing (well sort of easy) to replace and eventually will need to go so you might want to try that before moving on to the exotic stuff.

jralbert wrote:Another thing that comes to mind is the little (CG-11) fuel filter at the mouth of the carb fuel intake. Just a possibility. Usually when that thing needs to be replaced you can't get more than 1,800-2,000 rpm but once in a while you can push through. It's an easy thing (well sort of easy) to replace and eventually will need to go so you might want to try that before moving on to the exotic stuff.

Thanks, jalbert. Do you know a source for those filters? I'm downriver (Rockwood - Erie MP)

oops, @jalbert, I thought you were located in Detroit area... you are Chesapeake. My bad

Those filters should be widely avail. Out of active boating for some time now, I'm not the best for sourcing but I am positive I got mine from the neighborhood West Marine. Buy a few..they're cheap and I can guarantee that you will need to replace them again -
(UPDATE: It's avail as Fram cg11 -google it)