400ex acting up.

[dabrowat]

My 2003 400ex topend was recently rebuilt. It was running fine the other day, but now i have the same problem i had before. The quad basically runs better when the choke is on. today i wanted to ride it but when i put it into gear, it would die.

[dabrowat]

What can be wrong with the carburator atleast?? b/c when the choke is on and i gas it all the way the quad revs up. but when i turn the choke off and try to gas it, the quad dies. What can the problem be?

[Newrider08]

The problem is your pilot jet, take your pilot jet out and clean it with a fine wire and carb cleaner OR better yet go buy a 42 pilot jet and just replace it, easier cold weather starting AND gets the fuel you need down low

hope this helps, I have had this happen many times, always make sure you turn off your gas when its parked so you dont have gas sitting in your carb

[jelrod05]

check where you needle is hooked up and make sure ir is hooked up with th two little phillps screws.