in general my bike runs pretty well, everything is stock, mostly. no muffler baffle, no headgasket, needle on leanest setting, holes in intake cover. when i first start the engine it idles properly, but when i give it gas and then release it back to idle, it spins way too fast. if i let it idle for 10-15 seconds it slows back down to a proper idle. i also noticed that more often than not this happens in the first five to ten minutes of running the engine, not as often as when its fully warmed up. any ideas?