Engine Stalling

[JRedig]

Hey guys, first time posting in this forum. I've got an issue that seems to be rearing it's ugly head again on my boat.

The engine is a 2003 Evinrude 35hp 3 cylinder 2 stroke. We picked it up from Hallberg used two summers ago. When we initially got it, we went through some nightmare'ish service issues but in the end Hallberg rebuilt the carbs and replaced the entire ignition system and it has worked great most of the time.

What's happening now, is after running at WOT for 5-6 minutes the engine begins losing power slowly and all the sudden dies. It will be difficult to start and keep running unless I just leave it alone for 20-30 minutes. Even then though, WOT will only yield about 15mph (usually 25-27) and it will eventually die while at WOT. It starts and runs fine when cold.

This happened last summer, I thought it was the fuel line so I replaced that with a new evinrude specific unit. That didn't fix it entirely. Then I got to thinking it seemed like a bad tank of gas, so I dumped all that out including the carbs and started fresh.

It seemed to be fine until now. But this time I dumped all the fuel, added iso-heet, no real change. Still exhibiting the same symptoms.

Any idea's? I'm still thinking bad gas or maybe the fuel line is junk, again. Maybe the tank has a problem? The priming bulb seems to be fairly soft after it dies. But priming the line doesn't make it run better.

Thanks

Jeff

[marine_man]

Hmm...

I would check for spark the next time it dies and won't restart. That, and maybe I would do a compression check on it to make sure everything's good in the block. I don't think it's a compression issue because it wouldn't run all the great when it's cold either, but something to cross off the list of things to check.

marine_man

[eurolarva]

A rupture or crack in the fuel pump could be giving you the symptoms you describe. Make sure first that you are pumping water. I dont know evinrude but it sounds like a fuel pump issue.

[JRedig]

It is pumping water, plugs are new a few weeks ago, it does have spark after it dies. I'll do compression, but I too doubt it will tell anything.

I'll check the fuel pump closer tonight when i'm messing around in the garage.

Thanks for the tips.

Jeff

[JRedig]

Well, I went poking around the engine tonight and found a damaged oil injection line. At some point someone put a bolt in and caught the line under the head of the bolt. I doubt it's causing my problem, but not a fun find. Definitely makes me want to check the compression.

[knoppers]

your crank seal may be the problem, its losing compresion when its warm. that kinked oil line may be the culpret. you will need a new seal on the crank.

[boatfixer]

Actually what that looks like to me is the recirculation hose. Excess fuel can "puddle" with out those working right. If they are plugged they won't get rid of the fuel, if they are split or open they actually lean the engine out.

[JRedig]

I think that pinched line is part of the oil injection system. I'm still trying to figure out how it works. What is that cylindrical piece to the right and below the red circle I drew? I think it's a vacuum pump, both the oil injection and fuel lines connect to it on the bottom where it's square, it's round on the top where the electrical connections are.

I just need it to work for 4 more days!!!!! It's gonna get a new water pump once the season is over, maybe i'll just get through this weekend till muskie season is over and then had the repair shop have at it.

For now I guess i'll change that line, check compression and continue with the fuel swap idea. See if that helps.

Happy turkey day!

[boatfixer]

That part is the primer for cold starts. I didn't catch that right away. That line is not part of the oil injection. The oil is injected at the fuel pump. The primer takes gas and shoots it directly into the crank case per each cylinder with the push of the key, thats the 2 wires you see. If there is a hole in the line it will cause that cylinder to run lean which can cause damage to the engine. Whether or not thats the problem , replace the line as you planned on making sure there is no air leak.

It does sound as though its fuel related but i would want to know the temp of the engine when this happening to rule out over-heating.

[JRedig]

I'm down to thinking it's definitely fuel related at this point.

I changed that vac line, cleaned/gapped plugs and swapped all the fuel out. Drained the bowls, lines, tank etc. My truck is burning that off now without any issue, but the boat seems to be fixed with a fresh tank of gas.

Ran it today WOT for 25 minutes without a stall or hesitation. Started fine when warm and cold, had full power and no issues.

I really hope that's the problem, otherwise it's fixed and I don't know why!

Thanks for the idea's gents, tight lines.

-Jeff

[JRedig]

And that's two days of hard running with no issues. Stupid bad gas.

[boatfixer]

Good to hear.

[marine_man]

Glad to hear you got it figured out!

marine_man