1997 8hp yamaha with rough idle

[dfrants]

I got a 1997 8hp Yamaha 2-stroke model 8MSHW that I bought used.it starts on the first pull and runs great except when you try to idle it all the way down. then it "misses" and runs rough. I've gone through carb and made sure the fuel is good. tried two different fuels and tanks. could it be the head gasket?

 

[ondarvr]

If it starts easily and runs well except at a very low idle it's probably not a head gasket.

Does it miss, or does it pop back through the carb? A lean sneeze is common if the carb is dirty or not adjusted correctly.

 

[dfrants]

it's a miss. like a little water enters a cylinder or an air leak in a hose. it doesn't pop back through the carb. do you know what the rich/lean idle setting should be turned out from lightly seated?

 

[dfrants]

I have the rich/lean screw set at a little less than a 3/4 turn out from lightly seated. the plugs look tan and dry. when I run the motor at its slowest speed it will miss and run rough but doesn't all ways die out. after trolling for awhile, if I put her in neutral and rev it up alittle, all kinds of unburned fuel will blow out of the exhaust.

 

[dfrants]

It was the float. Whoever rebuilt this carb before I got it never correctly adjusted it.