Hey all I have a 1980 Puch that I’m working on for a friend. It sat outside for years and needed totally gone through. I’ve got it running now but it doesn’t sound like a 2 stroke. It is really slow to rev up even when it’s on the center stand. When I’m sitting on it to take off I can give it full throttle and I won’t move. I had to replace a lot of parts so I’m hoping it’s a tuning issue but I’ve been changing jets and messing with the airbox but nothing seems to change how it runs.
It’s a 1980 1.5hp Puch Maxi. It’s got a Boss pipe and a 15mm authentic Bing carb. I’ve got jet sizes 60, 62, 64, 66, 68, and 82. It runs a little worse with the smaller jets but the 82 doesn’t seem to make it act any different then the 68. My compression is somewhere between 120 and 140. My gauges shoots up to 140 but settles on 120. I’ve taken care off all the air leaks around the carb. Also running 15mm #1 Grandpa intake. Original airbox. Has a new point setup from treatland that changes the output to 12v and the timing is set at 17 degrees before TDC. Tank is clean. Gas mixed 40:1 with oil. Fresh transmission fluid. New 3 foot clutch from treatland with blue springs set to 15lbs. New piston and rings. Replaced the seals in the bottom end.
So it’s hard to start cold. Needs full choke and a few kicks. Once it’s going it idle fine but takes a little while. It’ll rev up but will die if you just go straight to full throttle. It doesn’t rev high and sound pingy like a two stroke should.
I have been repairing vintage motorcycles for years but this is my first two stroke. Any help is appreciated.