250EX running lean?

[Mr.Offroad]

I'm checking the valves on my baby EX the other day and I see the air snorkle is all choked off on the end under the tank. I figure it couldn't hurt to cut 'er open and let 'er breathe. I take 'er to the trails the next day and she sputters like a good thang in the higher rpm's. Check plug...nope, it looks great. Change plug...nope, it still runs like crap. Take out air snorkle and block off half of it and, BINGO! she runs great again. I just can't believe that's enough to lean it out, but it is.:huh

[moto93]

Yea, it's getting twice as much air now. You're going to have to go to a 105-110 main and lower the needle clip.

[2004TRX450R]

Ya those things are really tempermental to that amount of airflow change.