power

Hey all,

I have had my moped (1977 Puch) for acouple of years and I think I pushed it around more last summer than actually rode it. It has been in the shop for a couple of weeks getting new tires and a general check up before the summr starts. It is ready for me to pick it up however, I am told that it's only going 17mph. Same problem as last year. I had the points, condenser, spark plug rplaced. The carb is clean, gas mixture good, Cleaned the exhaust last year. Maybe doing that wiill help againbut it didnt really help before. points are gapped properly and timing is good.

Now this may be the most retarded question/statement ever on this site but here goes. I read once that someone had a broken horn and when he fixed it all the power came back. I do have a problem with my horn going off all the time but I have temporary fixes for that. Has anyone heard of such a stupid thing before? Does anyone know how and where to get a new horn and replace it?

Thanks for reading my rambling story for such a silly question.

Re: power

Some bikes are wired so that if a brake light or tail light or the horn or headlight fails, the ignition cannot work. This is someone's idea of a safety feature.. Or, more likely imo, it is an effort to conform with some local moped classification-laws that demand working tail lights or a horn, etc. Manufacturers need to get government approval before they can sell their bikes.

If that bike runs at all, i wouldnt suspect ignition problems. More likely it is carburation/fuel delivery or driveline troubles.

For instance, if the bike has a belt drive / variator setup, a broken variator will keep it in low gear.

And check out the entire fuel system from the gas tank to the engine block for adequate fuel flow and fuel or air leaks, etc.

Re: power

Jason Luther /

do the wheels spin freely? perhaps your brakes are dragging or the wheel bearings need to be greased. is the chain at the proper tension (there should be about 3/4 inch of slack). moving on to more complex problems.... have you had a compression test? is the choke sticking or is the airbox clogged? is it a one speed or two speed? maybe you are stuck in first gear.-jason

Re: power

The wheels do spin freely and it starts fine. It lacks power and I remember it stalling when I stop. I think the chain is fine. I seem to remember the mechanic fixing the slack. Unfortunately I don't have the same knowledge about bikes as most people on here do. I have learned through having to take things apart and guess. How do I do a compression check? The airbox, if that's the air filter, is also fine. I have good spark as well.

Ange

Re: power

My knowledge is limited about my bike so I have to ask what a variator is. I don't think it's a belt drive. I beleive the guy that has it right now replaced all the fuel lines, cleaned out my tank and carborater. Another guy I took it to last year made the holes in my exhaust bigger without telling me he was going to do it. It got louder but not faster. What's the best way to check for airleaks? I apologize for my ignorance but this is how a person learns I guess.

Re: power

here in lies a clue to your inability to get over 17 mph

"Another guy I took it to last year made the holes in my exhaust bigger without telling me he was going to do it. It got louder but not faster"

one if the ways to get more speed out of a ped is installing a performance exhaust, by making the holes in your exhaust bigger he reduced the back pressure the exhaust provides, with less back pressure the ped looses power.

so think back before the exhaust was altered did you get above 17 mph? if you did then most likely the exhaust is the problem.

Re: power

I think the reason he did that was to make it faster. I knew that didn't make sense but he grew up in Italy and has owned and worked on many a bike. He did this without my permission and it really annoyed me. Should I Order a new tailpipe? Is there a cheap place in canada? I ordered parts from the states and it costs a fortune. Ange

Re: power

Since you've had little sucess finding a competent mechanic and want to learn about your bike, you could start off by going HERE and grabbing all the Puch manuals .. there's bound to be very helpful information that applies to your bike in at least a couple of them.

Mopeds are just about the simplest form of engine driven vehicle known.. The learning curve is pretty flat. Given some small desire on your part, you'll be an expert at your own bike in short order..

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My guess is the bike is a chain driven, automatic 2-speed. Since, by law, mopeds must shift automatically they use something called centrifugal clutches. When the engine's rotational speed is high enough, weights are thrown outward and the clutch engages.. and the bike moves forward.

As road speed increases to some point (usually near 15mph) another clutch engages and shifts the transmission to 2nd gear.

A car thats stuck in first gear will not have a high top speed and nor will a moped. Since your bike runs fine up to about 17 mph, the transmission could be part of the answer..

The easy test is to drive it and listen to the engine.. As the bike shifts to second the engine RPM will drop, just like in a car.

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Variator:

Some mopeds don't use a roller chain to turn the rear wheel. They use a common V-belt and pulleys.

And some belt-drive bikes use pulleys that automatically alter their diameter, providing a range of "gears". These infinitely variable belt drive mechanisms are called variators.

Re: power

Thanks so much. I really appreciate the help. I do enjoy working on my bike. Makes me feel like a man!

I have many things I will try in oredr to get my power back. And extra thanks for the manual site. That makes my day

Ange

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