rpm

My 1994 KLR is having this phantom problem the mechanic can't seem to fix after three visits. Afer riding 20 minutes it will start stuttering a little and lagging and surging between 3800 an 4700 RPM, just not holding steady. Then sometimes this progresses to complete bucking with the...

Wondering if anyone has experienced similar issues with their KLR. http://www.youtube.com/watch?v=Ltptv5vARRc&feature=youtu.be Basically when I'm in gear and coming up to 3500 rpm my bike seems like its not getting enough fuel? I have cleaned the air filter, I am thinking im going to have to...