Yet another jetting question.

[ejm]

I have a 04 yz250 that I purchased new this summer. All of the posts about jetting I have read on here and else where have said the colder it gets the leaner your bike will get because the air is denser. When I bought it average temp was around 60 and I didn't foul 1 plug, now that its down to around 40 I am fouling plugs on average two plugs per tank of gas. I am running yamalube at 32:1 and am at sea level. So am I confused or is my bike confused and doing things backwards.

 

[KX02]

That is pretty strange. The colder weather will definitely make the bike run leaner. Perhaps you have some other problem in the carb or motor?

 

[ellandoh]

now that its colder you arent getting her warmed up proper ................twist it !!

 

[ejm]

Thanks guys, I will try warming up longer, this weekend should be a decent test because I am sure it will be even colder.