i was doing some mantaince today u know oil change new oil filter clean air filter and new spark plug. When i toke out the old spark plug the tip was black am i runing rich or is this normal.

A couple weeks ago i started useing 89 octange gas because my atv was backfireing cuz the bike was runing lean so should i go back to useing 87 octange gas.

 

Which model quad?

 

<div class="FTQUOTE"><begin quote>Originally posted by: jsgregg

Which model quad?</end quote></div>

06 Rancher 2wd

 

Octane has nothing to do with rich and lean.
If youre concerned about fouling the plug, get an iradium tip plug. But if you dont have any drivability issues...its jetted ok.

 

I think hondabuster is right.If it isnt fouling plugs then I wouldnt worry about it.Four strokes arent as sensitive as 2-strokes are when it comes to air and fuel mixture.If it is still backfiring though then someting needs to be changed but fuel octane will not fix that.

 

a little black is better than it being white....i would sat your ok......as long as the black is dry and not wet