Bad gas causing rough running at low RPM's?

[idunk]

Just bought a 1988 Bayliner Capri with a 125 HP Force. Idles fine and runs great at high RPM, but runs really rough, smokes, and boat shakes at lower RPM's. Have searched prior posts and have some ideas, but also was wondering if old gas could be the culprit or at least be adding to the problem. It hasn't been used much the past couple years and currently has 6 gallons of fresh gas along with a bunch of old stableized gas. Of course I can just drain the tank, but why do that if there is no chance it could help? Any suggestions? Thanks.

 

[south texas]

Re: Bad gas causing rough running at low RPM's?

Had a similar problem on my last boat. 1 Year old stabilized gas. Boat ran like crap.. I drained the tank, changed the fuel filter, filled with fresh premium and added seafoam. Solved my problem.. Either way, it doesn't cost much to try.

 

[idunk]

Re: Bad gas causing rough running at low RPM's?

That's kind of what I was thinking....just good to hear it validated by someone else. I'll do the same thing you did and hope for the same results. Thanks!

 

[south texas]

Re: Bad gas causing rough running at low RPM's?

If it's a pain to drain, you can buy a transfer pump from Harbor Freight for about 6 bucks. I bought one and it works well. I pumped out about 20 gal pretty fast. Also check if the tank needs to be cleaned while you're in there. Don't take any chances and end up repeating the process!

 

[idunk]

Re: Bad gas causing rough running at low RPM's?

Thanks for the advice South Texas!