hi everyone. i just bought a 2004 klx300r yesterday and when i test rode it had a flat spot right off of idle then picked up the r's after about 1/4 throttle. i assumed the carb may be dirty as the fellow only rode it once and it sat in the garage for 2 years! i cleaned the jets last night and that didnt seem to work. any ideas? i have noticed that the air screw has a cap on it and i suspect that this may be out of adjustment or maybe i didn't clean the air passage good enough. help! it's a new bike with 44 miles on it! thanx

 

I was hoping to see a reply to this thread. I have recently done exactly what you did. Bought a 2004 KLX300R that has 31 miles on it. Has been sitting in a garage covered for almost 2 years. When I first brought it home it would not idle. So I took the carb apart and found the pilot jet clogged. So I cleaned the jet as well as the entire carb. It starts and idles great now, but has a flat spot when cracking the throttle from idle.

 

did you clean out the tank and use fresh fuel? new plug? try posting in the KLX250S section for more responses

 

maybe its not jetted right, or the air/fuel screw is not in the right place...

 

Are you both running stock exhausts? If so, is the buttplug in or out?What about airbox mods or aftermarket air cleaners?

If it'sstumbling just off of idle, try adjusting the fuel screw. The EPA plug can be removed by carefully drilling a small hole in the plug,then using a sheet metal screw to pull it out. You will need to gently bottom out the screw while counting the turns to find-out where it was originally set. Once you have it back to the original setting, try adding 1/2 turn CCW (richer), than checking to see if off-idle performance has improved.

Good luck! Once you have the carb off the bike, it might be a good idea to see if you still have the stock main jet size installed. This would tell you if someone has already been tinkering with it.