I am working on my newest moped, a 1986 Trac Hawk, and I believe the timing needs adjustment. Here are the symptoms:
-Once jetted properly, the moped idles like a charm but when acclerating/cruising the rpm's fluctuate rythmically, and as a result power is very apparently sacrificed. The rpm's will bounce back and forth from normal rpm's to abnormally low rpm's and then back up again, so on and so forth. The best way I can describe this is like expressing the rpm's as a sine or cosine curve, with each period being about one second long.
-Uphill this effect is increased dramatically to the point where the moped slows down and eventually stalls, rpm's fluctuating all the way.
All I can think of that can cause this is the timing is out of adjustment. What effect on performance does advancing the timing from stock have? Retarding the timing? What do you suggest I do to solve this problem?