I had the identical problem. If, after heating up, your motorcycle also begins to idle around 3300 rpm no matter how well you adjust the idle when cool, your problem is the carburetors. It starts to rev higher by itself after a few minutes and gets ferociously hot, your gas mileage drops to around 16 mpg. I am not a mechanic, I had the carbs professionally redone with new needles, cost was $400. Problem completely solved.