So my Kymco loses power under load. After warming up and trying to speed up, it bogs down to 10 mph and eventually dies, if held at wide open throttle. I hear a reed-like sounding rattle/ sucking noise maybe. Checked air filter. It does fine if I never want to go over 20 mph. Seems to shift fine at first but when going full throttle, bogs down. I can back off the throttle and limp it back home going slowly. I have duplicated the problem over and over. I seems ok at first, starts right up. Good gas, good spark, no other electrical gremlins. It will rev strongly on the centerstand up to what sounds like WFO. It seems transmission related. I would appreciate any input? Thanks.