4OO ex not running

[biggun400]

Hey Guys! I'm new to the site, obviously. I just got my 400 down from Virginia. When I got it here, it was backfiring a lot when I down shifted or just let off on the throttle, but still ran pretty good. The other day I went to start her up and she would fire up for a minute and then just die. Before dying, it sounded like it was backfiring in the carb. Haven't had much time to look at it yet, but what should I do? She won't even start at all now. Help please.

[biggun400]

Anybody got a suggestion?????

[prepracing]

just a thought, but coming from VA, down to GA may need to change your jetting for the different weather.

[greg_gorrell]

yeah, it sounds like your jetting is off...maybe from and altitude change or just the weather/humidity in general. take it to a shop and have them jet it or if you know how, do it yourself.

[400exredrider]

lean, check the jetting on the thing, alot of people will run a 42 or 45 pilot and richen up the main jet, and also maybe raise the needle, do one at a time until you eliminate the popping

[biggun400]

Thanks for the input guys. I'll see if I can't get her running this weekend.