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From: Albrecht via MotorcycleKB.com on 28 Jun 2007 14:21
novascroller wrote:

>checked the plugs, the tips are light gray in color and the insulator
>is a very light brown.

That indicates that the heat range is correct and the engine is running good.

Are there any little little black specks on the insulator nose after hard
aceleration, once the engine stops "stuttering" and runs good?

Black specks indicate preignition before the actual spark.

--
Message posted via http://www.motorcyclekb.com

From: John on 28 Jun 2007 15:26

"novascroller" <novascroller(a)gmail.com> wrote in message
news:ntt783laogamfs11b9lm0sev4606ab4l6l(a)4ax.com...
> >1. Incorrect idle mixture screw adjustment. If the idle mixture screw is
>>turned out too far, the idle mixture becomes too rich and the
>>inexperienced
>>mechanic turns the master idle knob up to compensate for slow idle RPM.
>>This
>>uncovers the transition ports downstream of the throttle butterfly and the
>>engine get a rich mixture and fires every other stroke, This is called
>>"stuttering" or "8-stroking".
>>
>>2. Float level set too high. The engine is able to suck fuel out of the
>>float
>>bowls too easily and the engine stutters until the excess gas is cleared
>>out.
>>
>>3. Float valve sticks, making the float level too high and the idle
>>mixture
>>to rich
>
> checked the plugs, the tips are light gray in color and the insulator
> is a very light brown.
#
The plugs will clean up ok if it's only fouling occasionally. You'd need to
drive the bike for a while at the throttle opening that's causing the
problem and them stop and check plugs.
John.


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