1997 900 rrv,bike starts and runs fine around town,when you rev it to around 6000 in first and second it is fine when motor gets to 6000 in third gear bike acts like it is running out of fuel,if throttle is shut for a few seconds and then opened slowly bike runs fine again,or if i am in sixth gear and try to get above 4000 revs bike starts acting up again,have had carbs off and checked the diaphragms and made sure carbs jets are clean,have removed diaphragm in petrol tap and this made the problem slightly better,run out of ideas
Dave

 

Sounds like it has to do with the fuel level in the float bowl, so you probably have a sticky float needle or something, since the main jet is higher up than the idle jet, it would make sense that it would bog once it needed the main jet.