Hello everyone, just started using this forum, looks like there is alot of information here and alot of intelligent people, so hopefully someone can help. I just bought a 1993 xr600r and I love it. I rode and xr200r for years and the power difference is phenomenal, but here's my problem: it just doesn't want to idle for some reason. If I turn up the idle setting on the carb, it's a mikuni flat pumper btw, so that it idles nicely, then when I take off to ride it, it wants to drive itself. Meaning, when I let off the throttle, the rpm is so high that it's driving itself. If I turn the idle down low enough so that when I let off the throttle I get the engine braking, then it doesn't want to idle! I'm using pump 91 octane gas and I'm guessing that might have something to do with it if the compression is as low as I've read here it is. So, I'm planning on draining the tank and putting a fresh tank of 87 oct in but, is that all I can do? I'm also guessing a carb rebuild or valve clearance check, I don't know, that's why I'm posting, someone with some experience help!!! Thanks in advance.