Has any one had this:
Engine break down at high rpm's
it was at about 7-1/2 but now seams to be lower, about 6-1/2
I was thing plug caps; leads or coils. plugs have been replaced

 

Clogged air filter? Gunked up carburetors? No fuel flowing from tank to carbs? Don't know about this bike, but others I've had have demonstrated high rpm breakup because the battery was bad.

 

I had my suspicions about it being a fuel problem

I thing I might do my road testing - I will try hight revs in first gear easily, and then other gears under load, that may define it a bit better, do you think?

 

The main jet is too large to get plugged up, but the needle which pulls out of the main jet could. The jet needle is attached to the piston slide which slides up due to air pressure. Evaporating gas deposits gum on the walls, and the air bleeds clog, which prevent the slide from moving smoothly. I can't get to the slides on my my '90 without taking the carbs off. But the slides can be tested by lifting the slide with your finger and see if they close smoothly. If they stick at all, they need to be cleaned.

But before I did that, I would check the ignition advance using an old timing light. When the spark unit goes out, the ignition doesn't advance at all and the engine may not rev beyond 6k.