i just picked up a 76 xs500 with about 17,000 miles and finding that when riding it and im stopped, it idles at 2500 or 3000RPMs. Is this normal or too high? Also, im noticing now that there seems to be a little white smoke that is visible when Im revving the engine thats coming from the right side exhaust only. When at idle, the white smoke is not visible. The left side exhaust doesnt have this problem. Is this an indication of a valve seal leak? Thanks.