Rough Idle on Brand New 6HP Twin Cylinder Yamaha???

rpr

Cadet
Joined
Aug 26, 2001
Messages
16
I just returned from a vacation whwer I used the above motor for the first time. I went with a twin cylinder because it is supposed to run smoother, less vibration, etc. It runs fine above 1/4 throttle, but It seems a bit rough to me at low speeds. Not much, but I thought it would be smoother from what I read here.<br /><br />Is this normal in the breakin period since its running at a 25:1 instead of a 100:1 gas to oil ratio? :confused:
 

JasonJ

Rear Admiral
Joined
Aug 20, 2001
Messages
4,163
Re: Rough Idle on Brand New 6HP Twin Cylinder Yamaha???

Like anything with a motor, you have to wait until it is fully broken in before you can determine if there is a problem. All engines have to "seat" their parts, especially the rings and bearings, so I recommend just following the break in recommendations, and then go from there. good luck...
 

Fouled Plug

Ensign
Joined
Jun 29, 2001
Messages
935
Re: Rough Idle on Brand New 6HP Twin Cylinder Yamaha???

The extra oil will ceratinly affect how the motor runs at low speeds. After the first tank of break in mix (or whatever duration your manual suggests) I'd clean and gap the plugs and see how it runs. I've always been a bit nervous about running 100:1, choosing to err on the rich side a bit. You should have no trouble at the leaner ratio though.
 
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