i think there minght be something wrong. when i'm ridin in low rpm's i hit the throttle and it will bog down and i'll let off then hit the throttle again and it will hit the midrange like a banshee. and i'm not luggin it, this is in 2nd gear and it will even bog in first. i can't hit the throttle to fast or it will bog and hickup. my buddys 400ex doesn't do such a thing. he has a white bros e-series pipe on it so that might help. but i need help. it has more mid-range than my buddys piped 400ex with equal top end and it don't have any low end. and my sprockets are stock.
and my air filter is clean and i shut the gas off everynight when i put it away. any suggestions will be appreciated.

 

change the spark plug

 

Agrd. with Speed..

 

doesn't do anything. also there is a k&n filter on it and the jettin is stock, so would that do that?

 

yea jetting could be off

 

whats the elevation and temperature you ride in? is the filter your ONLY mod to the bike? any air box lid mods?

 

Replacing the plug wouldn't hurt or even make sure yours is gapped right.

No bottom end but good top end? Could be something clogged in the carb too. Clean it out. If it helps, buy a good fuel filter.

 

A bog when you quickly snap the throttle is usually your pilot jet...... As Cals400ex said is the filter your ONLY mod? A K&N may lean out your mixture, but I wouldn't think enough to make it run poorly. It sounds like your lean on your pilot, but this could be caused from a clogged jet.

 

yes, the exhaust is stock and the airbox is stock and i have to lid on it. i was thinkin the k&n made it run a lil lean. i already changed the spark plug (it was a bitch). so what u think i should do? this sounds like a newbe question but how should i go aobut cleaning to carb? take it off, take off the float bowl? carberator cleaner? thanx for the reply guys it helps alot i think i'm goin somwhere with this. i kno this isn't a big problem but i just want this bike to run as good as i can get it and i wanna learn from all of my experiences.

 

yep, i would remove the carb from the bike and take out the main and pilot jets and spray the heck out of the carb with carb cleaner.

the K&N shouldn't change jetting too much. my buddy ran one on his bike with stock jetting and it ran the same as my stock bike did. however, with you being in michigan it may be colder thus the air is more dense meaning your jetting could be lean. also, the elevation matters too.