boat problems need help

[Penn yan 88]

Been having issues since end of last year with my boat stalling at low rpms and bogging down when giving gas, basically running like crap. Issue does not seem to happen right away but about half hour into trolling. Did find some water in the fuel end of last year i changed the water separator and added some dry gas and it seemed to run a little better.

Had the shake down run last weekend and the boat ran great for the first 4 hours and then started to stall and bog down again, luckily made it back to te launch after getting the rpms up for a bit. Had the boat looked at this week and was told the problem was solved , the water separator was changed again for some water in fuel and was told to run with only 1 gas tank, well of course about a hour into fishing today the boat did not run good and had to keep the rpm's up around 1000 to 1100 to keep from stalling, even when I started back to port and raised the rpm's it bogged down then leveled out so i was able to get through the channel with out stalling, pulled the boat brought it home,took off the water separator and no water in the gas. Motor is mercruiser 350 5.7 liter fuel injected. Any suggstions would be greatly appreciated

[jeb1340]

Is their an inline fuel filter? Is there a fuel filter at the end of the fuel line that connects to the engine. I know there can be one on carbs but I don't know about fuel injection. Something quick and easy to check.

[Penn yan 88]

There is only one that connects to the engine,i was wondering the same thing if there should be a inline one also.

[Gill-T]

Stabil marine, or seafoam gas treatment.

[Penn yan 88]

I did add star tron to the tanks, i will have to try that also. just hoping fuel injectorsare ok

[traveling man]

did you check your spark plugs? what do the they look like?

[tree top flyer]

I might be off track but this is a common problem with mine also and im sure its the valve seals. Engines dont want to run that slow. If i run under 3 miles per hour without bags, my engine builds up and starts bogging down and fouls the plugs after awhile. How it was explained to me is that when a boat sits, the seals harden after a time and oil and stuff is allowed to build up at low rpms. I dont want to loose my boat for a week right now to have them re-done so if she builds up while we are fishing, I might drop her in nuetral and blow her out, you will be able to tell with the oil junk floating behind you. If that doesnt do it, will pull in the lines, Open her up and she will eventually clear out. then go back fishing. The bags work great in getting the rpm up and avoiding this. Might be your problem might not.

[Penn yan 88]

Plugs look good

Tree top flyer, did this always happen with your boat or did it always do it since you got it? reason i ask is i have had the boat for 2 seasons and it never happened before until recent.

[Boatino]

Sell it.

[woody 184]

py88,

I had the same problem with my Penn Yan 2 years ago and I changed the filters 8-10 times with minimal help. I had the same engine you have with the thunderbolt ignition. I thought the whole time the way it ran that it was water in the fuel until I spoke with a friend of mine who is a mechanic and he looked at me and with 5 seconds he said your coil is bad. The boat engine would start to get to normal operating temps and the coil would overheat and not send a consistent spark and no spark at times until it cooled down... I changed the coil and took her out and that boat purred like a kitten low speed and high speed.. I think if you put a new coil in her you will be fine..... Dale

[tree top flyer]

Yes but this the 2nd year with it and it did sit for 3yrs before that. everything else is done coill, rebuils carb, etc, etc. Could a numerouse things, from , water , rich carb, but once those things are eliminated witch sounds like you have looked at. valve seals on a 20 year engine, same year as mine are worth looking at.

[Penn yan 88]

tree top flyer, thanks for the info. I will look into to be safe but the boat is a 99 so i would not think it would be a valves.

Woody 184, that is encouraging because it does not seem to happen until the boat has been running for a little while. I think the biggest pain about this all is a lot of mechanics around do not have a computer due to the fuel injection.

[Penn yan 88]

Boatino. make sure you call for fishing info. I will make sure to tell you exactly where they are biting.

[reel drag]

Are we talking about your boat Rob? Call Tom Barberra 585-392-7304

[Penn yan 88]

Joe, i left him Tom a message Saturday, waiting to hear back from him.

Rob

[Legacy]

penn yan 88,

Im sure Tommy was probably down at camp this weekend.

[reel drag]

I'm sure he can help you out.

[Penn yan 88]

i have heard nothing but good things so i am looking forward to hearing from him

[Feelin Reel]

Had the same problem with my Penn Yan had the card rebuilt and never had another problem with it. Mine was a volvo penta

[Feelin Reel]

I mean carb

[tree top flyer]

Sorry, by your name i was thinking the boat was a 88. lol

[Penn yan 88]

Well i was told today i needed a high pressure electric fuel pump. Just got back from the red cross charity charter at the genny so will pick the boat up tomorrow and test run it. I appreciate everyone's input. Hopefully this is it and i can start fishing on my boat again

[tree top flyer]

good luck.

[Crestliner24]

I had a similar problem two years ago, it would runs fine at low RPMs then would skip or bog down at full speed. It took one good boat mechanic to find the problem. I would check the fuel pump.... there is a small tube that runs from the pump to the carb. Check the tube for any fluids (it should be clear). After I cleared the tube out... it has been running great.... If it continues to have fluid in the tube, you will need to replace the pump. Hope this helps.

[Gezijamez]

Could be due to cold water rings dont seat well if not hot enough and fuel does not burn right creating a carbon build up I had same problem several years ago and put hotter thermostat in re-adjusted carb (lil more air) and it corrected the problem. If that any help.