03 raptor, rode it for about an hr and then WOT run...and plug was white...it was about 40degrees out...I have full yosh. and k&n filter and jet kit installed...and 2 1 1/2 holes in filter lid...I took it back to the dealer and he said it could be caused by temp...the did the jetting...there are no sympthoms of lean beside plug..no backfiring, dieing on topend nothing...im lost...pls help....

 

possibly could be caused by temperature.....but i dunno if 40degrees would make much of a difference.

 

Did you find out where your jetting was at after you asked this question yesterday? BTW, a white plug doesn't necessarily mean you're lean.

 

Temp does effect jetting alot but generally the air/fuel mixture leans out when it gets warmer. If it's not acting like it's lean then it's not, just leave it how it is. If the bike is stock and something goes wrong because of that it's Yamaha's fault and they should cover that under warranty.

 

it would lean out when it is colder I believe

 

my bad...

 

Hey guys thanks alot...Haysee, as far as the jet size that came with my Yosh. full system and k&n filter and jetkit, im not forsure....i guess i should start learning these things..but if you guys think it is ok...i trust you guys....Like i said it does not back fire or fall off on top end.....when i do shut the motor off you hear a little puff or almost like a small back fire....thanks guys

 

What octane of gas are you running?

 

im actually running a combination of 87 and 92.....

 

If the plug is white, then it is definitely lean... if it were mine I'd richen it just a bit, cooler weather will have that effect, but usually it takes quite an extreme to make a visible difference. I like to run on the rich side of perfect, you get better cooling of valves, piston, etc that way.