I'm new to the web site so be easy on me. I just purchased a 1988 xr600r which the engine just went through a $1500 overhaul (piston,ring,timing chain, etc) in Jan 03. I have been having trouble starting the thing. It usually takes around 15-18 kicks. Once the thing is warmed up it runs strong. But one thing, right after it grabs hold and tries to start, there is a pop at the bottom end of the idle. I usually have to keep my hand on the throttle at a mid rev to get it warmed up, but once it's hot, it will idle all day with no problem. The bike was put back to stock even with the correct jets. Where do I start, besides cleaning the plug and carb? Interesting note, the automatic decompression was removed and I use the manual everytime.