KZ750 twin problems

I need help. My 750 twin starts cutting out and sputtering when I go over 75mph. When I start out I have about 5 minitues to go as fast as I want then it starts sputtering. I've changed the petcock, filters, points, coil. I'm running out of things to replace and the town I live in doesn't have a good shop. Any ideas?

At the risk of suggesting something unsafe, try running down the road with your gas tank cap unlatched. It just might be that your tank vent is clogged.

kzcsi