49cc huasheng problem . Please help


New Member
Oct 6, 2019
Hi guys I just finished building a cruiser with the 142f 49cc huasheng and I'm having an issue . When I first got the bike together and went and rode it and was only getting 20 mph out of it and it seemed sluggish and held back . I played with the alignment of motor sprocket and rear sprocket and it seemed problem was fixed . Throttle response and top speed was at 30 mph .well I rode it over some bumps and now I'm bad down to 20 mph . But this time the motor sounds different . Just sounds restricted and has noticable powerless , throttle response and lagging top speed . I checked all my alignments thinking it jared lose but it hasn't . Any ideas ? Could something in the carb been Jarred lose ? Idk I'm stumped