1977 puch maxi

sometimes at idle my trans makes a knocking noise is this bad?

ps. i have a 1 speed

Re: 1977 puch maxi

Are you sure it's not the engine ? If it is indeed the tranny, the first thing I'd do is check the starting lever for proper adjustment, drain the ATF out and check it for metal, then refill it to the correct level using "F type" ATF and try running it again. It could be clutch plates sticking, if it still knocks then it'll have to be opened up for a closer examination.

Re: 1977 puch maxi

well I drained the oil last week and i think the guy who i bought it from used motor oil insted of ATF,anyway i put ATF in and the knocking seemed to go away,but once in awhile you can still here it. should i worry or just drive it.

ps. during winter im repainting it and putting a 70cc kit on.

Re: 1977 puch maxi

If the knocking goes away at a higher rpm you may have "piston flutter" This is caused when the bearing in the connecting rod where the wrist pin goes through has become elongated instead of round. So at lower rpms (idle) you get a clattering sound. Rev it up and the momentum of the piston moving rapidly up and down compenstaes for the slack and the clatter goes away.

At some point you should do or have done a "Top End" overhaul, new piston, rings, cylinder honed or bored, new wrist pins, bearings, etc. If you don't want to do it yourself you can pull the engine and ship it off to have it done if there is no one in your local area.

Re: 1977 puch maxi

Ron Brown /


I dont know much about Puch other than you seem to have a primary transmission of some kind. It is not unusual to have a little backlash which will cause a knock at idle because the engine is speeding up and slowing down as it does the typical 2 cycle idle.

Try rocking the rear wheel back and forth while on the center stand and see if you can reproduce the noise to figure out exactly where it comes from. If it seems to be the transmission and goes away as soon as the engine smooths out, ignore it.

You might also check the front sprocket and make sure it is correctly attached.


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