I bought this bike for just $500, and it was running, but I didn't initially notice some of the problems that it had. I've spent some time on it and it's in good working condition except for the fuel mixture. It pops while engine braking, and it looks like they took out the spark arrestor to get more power. I've checked for vacuum leaks, and there aren't any anymore. I ride between 4,000 and 9,500 feet above sea level. The bike will go anywhere now, but without being sure of the mixture that I'm running I hesitate to take it on long rides for fear that it overheats and strands me somewhere. Does someone with more experience with this bike know an easy way to jet it?