Moped Fixed

My 1978 Puch had no power all winter long, top speed 20 mph, I thought it didn't like the cold, because when it warmed up it seemed to run a little better. But yesterday it was 55 degrees out and top speed was still 20 mph. So my first step was to clean carbuerator. Cleaned carbuerator put it back together, then it ran worse than before. My next step I started draining the gas out of it to clean the gas petcock. Took out petcock and the rest of the gas flowed out with some crap that was inside gas tank. Cleaned petcock, put back together, and now it runs great. I also cleaned the Points using Fred tune up tips, great idea, thanks Fred.

I am thinking about a BI Turbo for my moped, does everybody think that a BITurbo is worthwhile.


Re: Moped Fixed

Reeperette /

Yes, Bi-turbos rock, but thanks to the picture I think I've spotted your top speed problem right away.

That appears to be an oversized rear sprocket with mini on the front - that's a power takeoff mod that does nice things for accelleration, but causes topspeed to completely suck.

Now, since I am not too familiar with Puch, not as much as some here, I cannot tell ya if that one is built like that stock from the factory, it don't look like it to me, tho.

Probably jumps real good up to the 20mph, but don't go no faster, now that you've cleaned and tuned it.

My reccommendation here would be a smaller rear/larger front sprocket or possibly both, you will lose takeoff, but get it back at the top end.

Nice ped guy, looks like ya take good care of it.


Re: Moped Fixed

Ron Brown /


If cleaning the carb made it worse then it may be running too rich. Take off the air cleaner and air box and see what happens.


Re: Moped Fixed

The petcock was partially clogged, now top speed is 30mph like it was last summer, and maybe 35mph down a hill. The problem is the gas tank has rust in it so I will probaly just clean petcock and drain tank as a yearly maintenance item. It was hard to figure out what was going on because when you pulled the fuel line and turned on the gas, it looked like the gas was flowing freely. But it didn't let enough fuel through to go top speed. It still idled perfect and started right up. I wanted to post this, because the key fact here is the fuel flowed freely with petcock open, giving the appearance the petcock was OK, but it did not let enough fuel through to reach full throttle.

Re: Moped Fixed

Ron Brown /




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