Honda 9.9 idles rough

[Bapof]

My 1984 Honda 9.9hp outboard idles rough sometimes, (usually when I bring my sailing boat into the marina). It runs OK at high revs, but stalls when at idle speed. Other times it is perfect. I have had the motor checked by a mechanic and they cannot fault it (they did not have my fuel tank or connecting tube). I have replaced the fuel in the tank with no change. Any ideas?

 

[gss036]

Re: Honda 9.9 idles rough

Turn your idle up a little bit. Use the adjustments on the carb to do this. There is also a fuel filter right beside the carb, check it out to see if it has any junk in it. Shoud be a see through filter. Being a 1984 model, may be a little different than my 1998 model.<br />How is the gap on the spark plugs? That could be a problem at idle if the gar is too wide.

 

[hondon]

Re: Honda 9.9 idles rough

Sailboats offer up all kinds of interesting situations.Is that engine mounted in a well that might be allowing it to breath it's own exhausts in a tail wind?Tides and the wind can have these effects.Any bottom fouling?Has this engine been like this since you've had it ,or is this something new?You have to wonder what is happening between that clean bill of health at the shop and your situation.Borrow a fuel source you know works and see if the problem go'es away.