1995 Mercruiser GM 350 V8 engine stumbles and falters under load.

[Scubadave16]

Good evening.

I am new to this forum and have a question. I have a 1995 Maxum SCR 2400 with a Mercuiser 5.7L V8. Had it out on the lake Saturday skiing with no problem for a couple hours. After a short break i tried to pull a skier up and could get no power. The engine would only rev up to about 2500 RPM before faltering. It kind of sputtered a bit and the RPMs would drop and then pick up then drop again. In neutral it would rev up to over 4000 RPM. It runs fine at idle speed. The transmission seemed fine. The boat shifted normally and would drive just fine at slow speeds, but wouldn't go faster than about 10 mph. My Dad thought he smelled fuel in the exhaust but I didn't. Haven't had time to check anything yet, but suspect fuel flow issue. The tank was filled last week at the marina. There was no backfiring or knocking or black smoke as far as I could tell. I am hoping it is a fuel filter that may have picked up some crap that broke loose from the tank when i was turning fast to pick up skiers since i normally just cruise in the boat. Any ideas or places for me to start looking?

If I didnt post this right please let me know as I am new here.

Thanks in advance for your help.

 

[greg82255]

Re: 1995 Mercruiser GM 350 V8 engine stumbles and falters under load.

I'd start with the water separator fuel filter. Remove it and pour the contents into a clear container so you can see if there is any water in your fuel. In addition, check any inline fuel filters you have. I'd guess you aren't far off, something may have just gotten in your fuel line and plugged it up.

 

[kmarine]

Re: 1995 Mercruiser GM 350 V8 engine stumbles and falters under load.

I agree with the fuel issue begin with the filter. If the boat was stored for a long time you may have stirred moisture from your tank bottom. I like to put a fuel pressure gauge between fuel pump and carb to see if you have enough pressure. Do you have a mechanical or electric fuel pump? begin there good luck.