Got the bog

terrywilson88

Seaman Apprentice
Joined
Jun 15, 2009
Messages
47
Hey guys, I have a 1986 Monarch fish/ski with a 90hp Evinrude out board. The mixed gas has been in there for a little while and I can't remember the last time I put sea foam in the tank. Last Sunday she would run for 5 minutes then bog down but would idle just fine, I would let it sit for a minute and go back on plane. Checked the primer bulb and it was full. Ran the motor at home and saw no leaks. Do you think it could be water or just old fuel?
 

archcycle

Chief Petty Officer
Joined
Sep 21, 2009
Messages
647
Re: Got the bog

If you've got doubts about the fuel toss it. Or else at least fill a small portable tank with fresh fuel and test if you've got more in the main tank than you want to sacrifice.

As for the water, do you have a fuel/water separator filter inline? And if so does it have a new canister on it? They are about $6 at walmart and ought to be replaced annually
 

terrywilson88

Seaman Apprentice
Joined
Jun 15, 2009
Messages
47
Re: Got the bog

No inline filter. I've been thinking about installing one. I think I have about 10 gallons of gas in the tank that I could drain out or should I put some sea foam in?
 

jtexas

Fleet Admiral
Joined
Oct 13, 2003
Messages
8,646
Re: Got the bog

If its over six months or so, replace it. Adding seafoam to bad gas is just a waste of seafoam. sorry once it goes bad it's just bad. you could burn it in your truck, a little at a time added to a full tank. these modern automotive engines got all kinds of sensors and computers to deal with poor fuel.

You might have other problems, but lack of confidence in the quality of the fuel will sure enough complicate the troubleshooting process.

Meanwhile, I'd do a compression and spark test; once those are ruled out you can focus your attention on fuel delivery.
 
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