
hi, i am a mechanic but still new to the bike world. i am only 19. so i have very much to learn. a customer at my work brought a bike in, 98 gsx600 which would not start. i got it started, in fact it was a major valve timing problem, which the guys in the shop were very impressed i figured out. but now, the bike runs so well in neutral, but as soon as it is in gear, it runs good only to about 6000 rpms. now in neutral, i can rev it to the redline almost and hold it therer for as long as i want. so i imagine there is plenty good spark, and enough fuel flowing to float bowls in order for it to fun like that while in neutral. again i have GREAT spark, the carbs were just cleaned twice, i synced the carbs today, and still it bogs out at 6000 and will not go above eight thousand. no one in the shop i work at can figure it out. it is driving me nuts. please help asap. there are stock jets and stock exhaust, perfect valve timing and valve lash, and brand new plugs. cleaned almost everytime before we try it again. the fuel from the petcock is flowing nicely, and i did checks on the pulser generator, it was good. it seems odd it only does it when a load is on the motor