1986 OMC 2.5L engine bogs down

[salinecountykid]

Engine starts immediately everytime, runs great for 8-10 minutes at any speed, then hear thump like hit something and engine bogs down. Will run rough at approx 25% power. Let sit for 10 -15 minutes and will repeat as stated. Drained gas tank thinking maybe water, some but continued symptoms afterwards - new to this boat so haven't tried anything else, thanks for feedback!

 

[Haut Medoc]

Re: 1986 OMC 2.5L engine bogs down

Welcome to iboats <br />Have you tried running it without the gas cap?<br />My guess is a clogged vent or pick-up.....JK

 

[salinecountykid]

Re: 1986 OMC 2.5L engine bogs down

Expert or inexpert always welcome...pick-up???

 

[Boatin Bob]

Re: 1986 OMC 2.5L engine bogs down

Pick up is the fuel pick up tube in the tank, usually have a screen over them to prevent it from sucking up crap from the bottom of the tank, if your screen is partially plugged you could be unable to draw enough fuel and slow down, the gas cap trick is to determine if your vent line is plugged, if air can't enter the tank to replace the fuel then you get into a vacumn situation that eventually the fuel pump can't overcome, sort of the same scenario, engine becomes starved for fuel.

 

[whywhyzed]

Re: 1986 OMC 2.5L engine bogs down

That thump could be the fuel tank pulling in because of the vacuum...

 

[salinecountykid]

Re: 1986 OMC 2.5L engine bogs down

thanks!! When draining the tank there was an unusual amount of "crap" coming up with the gas...I'll check the pickup tube screen.

 

[sdelamarche]

Re: 1986 OMC 2.5L engine bogs down

I'm having a similar problem... See my posting Spun prop, gas, electrical... Let me know how you make out..

 

[Gary H NC]

Re: 1986 OMC 2.5L engine bogs down

I'm with hystat on the thump noise..fuel tank getting sucked in..<br />Run it untill it bogs down again and open your gas cap..see if you hear air rush in.

 

[salinecountykid]

Re: 1986 OMC 2.5L engine bogs down

Headed to lake this weekend will try ideas, thanks to all!!

 

[rjwoodrome]

Re: 1986 OMC 2.5L engine bogs down

,,,