Puch Newport trouble shifting?

Motobecane Master /

I've been fixing up a Puch Newport that my girlfriend bought. I've done a lot to it so far including cleaning the carb, cleaning and coating the gas tank (which had chunks of rust and also an oil measuring cup in it), cleaning the muffler, and changing the transmission fluid (type F).

What it's doing is two things which I think are seperate problems. It runs great once started but tops out at around 15-20 miles per hour at which point giving it more gas just causes the engine to rev and nothing else. I think it's not shifting right and I have no idea what to do about that.

Second, it won't idle properly. It'll idle for a bit but eventually it dies out. I've tried adjusting the idle screw but it doesn't help. Would giving it a new spark plug help this? It looks like it's still running of it's original.

Any help would be greatly appreciated. I'd like to get this thing finished.

Puch Newport trouble shifting?

Motobecane Master /

Well I'm going to change the transmission fluid again and put in the amount that the Service Manual says to (9 1/2 oz.). Originally I had filled it until it was coming out and then I just put the screw back in. Hopefully that'll help.

Also, on the same page in the manual there happened to be a part about adjusting the throttle cable. It says that the idle screw won't work if the throttle cable is too tight. I also know that the wheel does turn slightly even when it's idle so I think that this might fix that problem.

I'm gonna go and do those things right now but if anyone has anything to add or suggestions of different ways to tackle these problems let me know!

Puch Newport trouble shifting?

Motobecane Master /

Yeah, that stuff didn't help. Anyone have any suggestions?

Re: Puch Newport trouble shifting?

See Ya Moped Army /

Decarbonize the entire exhaust system from the exhaust port on the jug to the end of the muffler. A clogged exhaust system will cause a major loss of power and not allow the motor to upshift.

Re: Puch Newport trouble shifting?

I'm having the same problem on my MK2. We cleaned the whole sucker out and it was still doing it. So, I'm gonna chalk it up to needing new piston rings. My motor has over 9k miles on it so it would make sense I have shitty compression. If the cleaning out doesn't work, maybe that's your culprit?

Re: Puch Newport trouble shifting?

Motobecane Master /

I just noticed the warning on the Puch that says "Do not use unleaded gasoline". What would that do to the moped? Where do I get regular gas?

Re: Puch Newport trouble shifting?

See Ya Moped Army /

regular leaded gas has not been sold for almost 20 years now. Unleaded is fine.

Re: Puch Newport trouble shifting?

If it revs and still doesn't shift,it may have blown or stuck second speed clutches. don-ohio

Re: Puch Newport trouble shifting?

Motobecane Master /

What can I do about that?

In other news, I can't get the damn thing started now. I'm going to be messing around with it tomorrow evening. Anyone have any suggestions?

Re: Puch Newport trouble shifting?

Motobecane Master /

How can I fix the clutches? I'm not very familiar with messing around with anything but the carb and exhaust and such.

I'm thinking it's that because the compression seems pretty good and I've tried running the moped without the muffler on it and it still does the same thing.

Also, I got it running again. Two days of frustration solved with a new spark plug.

Re: Puch Newport trouble shifting?

You have to disassemble the tranny somewhat. Go to www.mopedriders.com and look at the manual in the `moped repair' section that is for your engine/tranny. It will cover how to replace the clutches after inspection. don-ohio

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