Yamaha 200 weird Idle problem

[on/off]

I have a 1991 Yamaha 200 with a weird Idle problem. It idles grerat on the washdown but not in the water. Dockside it misses bad and after a min or 2 will stall. Back on the washdown it will idle all day. I pulled the plugs and they look fine. Any ideas guys?

 

[jim dozier]

Re: Yamaha 200 weird Idle problem

You cannot evaluate the idle of a 2 stroke during washdown on muffs. They will idle out of the water splendily on only 1 cylinder with intermitent misfires because they have no backpressure on the exhaust. If it won't idle in the water in gear then it has a bad idle and the engine needs work. Anything from a new set of spark plugs to a carb rebuild. Give us more info on the history. Did it happen all at once or has it slowly deteriorated over time? What has been done to the engine and when?

 

[on/off]

Re: Yamaha 200 weird Idle problem

Thanks for the reply Jim, it did deteriorate over the last 5 outings. 250 hours ago it had a complete rebuild. During the time it started the miss I changed the plugs with no positive effects. I replaced 1 coil that did not ohm out like the others and that didn't help either.