when the engine is relatively cold it will rev out to about 7200 after it warms up it won't pass 6200. My sledhead cousin figures it could be the weights. I've tried everything else. Any ideas

Are the carbs in good working order with the proper jets, float levels and choke plungers fully seated? Or it could be that it is pulling in hot air from the engine compartment. Are you running the stock airbox or does it have pod filters on it?
Are the clutches clean and shifting properly? Maybe when it is warm the secondary is hanging up.

carbs have just been rebuilt, I am running the stock airbox, and the primary clutch is pretty much brand new I'll have to look at the secondary. What advantage are the pod filters??? It could be possible that the engine is pulling in hot air, I'll look into it. Thanks

Pod filters will give you all kinds of grief. It's good you don't have them.