Puch Moped inconsistent throttle

Nikita Ephanov /

The Puch Maxi MKII works completely fine someday, but sometimes, after 5-10min of use it starts dropping speeds, and when the throttle is applied, it jumps and only partially accelerates,then decelerates and repeats. It may return to normal for a bit of time, and sometimes the engine dies out, but starts back up immediately. We are thinking it could be the engine's sensitivities to the oil mixture, or it overheating. Anyone else had similar issues?

Also missing some small gaskets in the carb, should i replace those, is that a major problem?

Also the moped seems to work better after adding fresh gasoline. (edited)

Re: Puch Moped inconsistent throttle

There is only one gasket needed on a Bing carb and that is the bowl gasket and if its bad you will know by leaking fuel.

It sounds like its running lean which could mean an air leak.

Check the intake manifold to head bolts and the carb to manifold bolt are all tight. Be careful its aluminum don't over tighten.

You might need to clean the carb if that hasn't been done in a while.


Re: Puch Moped inconsistent throttle

this sounds distinctly like improper fuel flow. once you;re going WOT for a while you drain the gas from the carb's float faster than it's filling and it stutters back. sometimes it can fill back up enough to keep going and "it jumps and only partially accelerates,then decelerates and repeats"

other times it dies, you pull over and it has time to fill a little back up and "the engine dies out, but starts back up immediately"

Basically i'd be try'na clean the petcock, fuel lines and fuel filter.

Re: Puch Moped inconsistent throttle

Blaine- The artist formerly known as Plumber Crack "(OFMC)" /



Restriction in fuel flow from the tank in to the bowl. A gas cap that is not venting properly can give you similar symptoms, but my bet is on the petcock screen or the screen at the banjo fitting of the carb if it still has one.

Re: Puch Moped inconsistent throttle

With the fuel on, disconnect the fuel line from the carb and make sure it is a steady stream of fuel flowing, if it dribbles you need to clean lines and filters. You could also have some piece of crap in your crab bowl that is clogging the jet when it gets sucked up.

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