ZXR750 J1 Bike seems to lose RPM

HI I am new to this forum,actually I only registered 5 mins ago.
I am hoping that someone here might know what is happening with my ZXR750.
The bike has an intermitent problem.When cruising along after the engine is hot doing say 6000 rpm the motor loses rpm and drops 3 or 4000rpm for a few seconds and then the motor runs fine again for a short distance and it happens again.
Has anyone got any ideas, or know of a BIKE auto elec that might and won't charge the earth?
Thanks Peter.
I am hoping that someone here might know what is happening with my ZXR750.
The bike has an intermitent problem.When cruising along after the engine is hot doing say 6000 rpm the motor loses rpm and drops 3 or 4000rpm for a few seconds and then the motor runs fine again for a short distance and it happens again.
Has anyone got any ideas, or know of a BIKE auto elec that might and won't charge the earth?
Thanks Peter.