My friend is going to upgrade his kids 250ex with a Yoshimura pipe, and k&n filter. Can any one recommend a good starting point for the carb? we are at 3,000 feet. thanks

 

I put a FMF Megamax and Uniflo filter on my wife's 250ex and the FMF web site said to run stock jetting.
We ride from 500'-3,000' elevation and it is a little lean. I just picked up a 100 jet today and will install it tomorrow to see how that does.

We had it down at the dunes in Oregon right after I piped it and I put in a 112 jet and it was bogging due to not getting enough airflow. I cracked the airbox lid in the back and it ran very lean.
I am going to install a couple airbox vents and rejet it with the 112 again before we head to the dunes again and see how that does.

 

Im about to go through the entire motor, rod bearings are bad, wonderin if you know wher to get a kit, larger cam? rod&piston etc.? also wondering if I may have to change out the carb, if I modify it too much, or will more airflow&jetting may do the job? ,, thx Frog

 

powroll makes a kit.