Persistent stutter accelerating under 3500 rpm on '96 750.

Bike idles and runs great. This 96 750F has 55K. Under hard acceleration below 3500 rpm it stutters badly. Over 4000 pretty smooth.

Where do I start?

 

Stutters, or shutters?

Due to the uneven firing order of the engine, it doesn't like to hang out below 3500 revs. Both my bikes vibrate if i take it below that threshold.

But, don't accelerate hard from below 3500. It's not good for the clutch, with the pulses being further apart and choppy. Roll on the throttle smooth until after 4 or 5 and then give her the schtick.

 

Do the PAIR valve delete.

 

Opening the throttle wide at 3500 rpm or less is asking for trouble in any gear over 2nd.