OMC bogging down at WOT

[SpartyOn]

I have a 1995 5.0 omc on my Four winns 200 Horinzon. It was running great until this year. The problem is intermittent. Sometimes it runs great around 5000 rpms and 41 mph. But at times(more and more) with the throttle wide open it acts as though something is holding it back. It acts like it wants to go but then bogs down and won?t go more than 3500 to 4500 RPMs and 30 to 35 mph. It seems to run fine in neutral or even at 3/4 throttle. I have went through several tanks of gas and have been putting stabil "blue" in the gas as recommended by a local marina. It has a new carb on it. Sometimes when I back off the throttle and then go WOT again it will run normally for a little while before acting up. Other times it just wont get above 35 mph and does not feel like it has its normal power.

The problem is hard to describe but any help would be greatly appreciated. I took it to a local marina. Of course when they ran it they could not find anything wrong as it would not "act up" Thanks for any help.

 

[vip-vindicator]

Re: OMC bogging down at WOT

Have you checked the choke to make sure it is not closing up?

 

[rbh]

Re: OMC bogging down at WOT

could the advance be sticking? the distribuitor cap and rotor are clean and dry?
throttle linkage is not loose and floating?
rob

 

[SpartyOn]

Re: OMC bogging down at WOT

Thanks for the ideas. Unfortunatley, I know little to nothing about engines. I am searching for ideas in hopes that my brother in law or father in law may be able to check them out.

 

[dhondarider]

Re: OMC bogging down at WOT

i have a similar problem with mine. its a 1988 omc 350 king cobra four winns liberator. only i cant go above 2000 rpm. but it runs perfect in the driveway. ???? only acts up in water. checked the esa modules... ohmed out ok. but i would check things like that every forum i go on says it could be the culprit

 

[Brucebu]

Re: OMC bogging down at WOT

I have a similar issue with a 1988 GM 350. Most are blaming the fuel system. I have rebuilt the carb, changed the filters, will change the fuel pump, tuned up the ignition. I will clean the fuel lines and pick-up screen. I was advised to use compressed air backward through the fuel line from the first filter back. OPEN THE FUEL TANK FIRST TO AVOID OVERPRESSURE. Also I was told to clean the fuel tank vent line as if that is clogged it will restrict fuel flow from the tank at WOT. Gonna lake test mine soon. Hope we are both good to go for the rest of the summer!