My buddy just bought a '03 CRF450R. The guy just had it rebuilt and has new SS valves. It is very hard to start when it's cold. And also, doesn't quite have the compression that my WR has (I mean that it is easier to kick over). We have tried all the recommended starting procedures for this bike, and it takes at least 50-75 kicks to get it started when it's cold. Once you get it started, or warmed up it's really easy to start. Does this sound like a valve issue or maybe something with the carb? I'd hate to have to check valves if there is somewhere I should start looking first.