Omc 350 rough idle and strong fumes.......

[debni]

Hi, newbie here. My 92, omc king cobra has been acting up on me and i can't finger it out! Thought I'd try a hail marry here. It was running flawless all spring but then last week i couldn't get it started. Turns out the choke flap was stuck, i had to poke at it pretty hard to free it. It ran good for about half an hour then it wouldn't idle without the throttle about half way to full, and even then it ran rough with very strong fumes. Changed fuel filter ( no water in it ), and played with the idle screw, got it running but it's still really rough sounding, and the fumes are unbarable! Also noticed some grey particulate in the exhaust water. Any help would be sooo appreciated! Trying really hard not to take it to dealer.....
thx

 

[shawnspawn]

Re: Omc 350 rough idle and strong fumes.......

which engine\carb setup? my rochester 4brl carb was overflowing gas into the manifold because of an incorrect float setting. The motor would start but run really ruff and eventually die once too much gas started to pool. this is easy to find out just by looking down into the carb while the engine is running and you will see excess gas dripping into the manifold. If you have the rochester carb it is not to hard to take apart and rebiuld with a seloc manual and rebuild kit. While its apart you can also check for water and other build up inside the carb.

 

[debni]

Re: Omc 350 rough idle and strong fumes.......

yah, there's alot of gas pouring in there. I was wondering about that. Guess i'll have to get the manual!
thanks mucho

 

[Donzi GT250]

Re: Omc 350 rough idle and strong fumes.......

Yep had the same situation with my 350 OMC and Quadrajet.
The repair shop rebuilt my card and had the float level way out of adjustment.
She would idle rich and rough.
In fact it was so rich the idle adjustment screws wouldn't have any affect when trying to lean it down.
Payed for a second carb rebuild from another mechanic and all is well.
Your float is probably stuck.