Puch Maxi acceleration problems

Full disclosure - I am not experienced with engines, I have toyed around and researched Puch motors since I bought mine last year.

My Puch Maxi (kick start, unknown model/year) can't propel itself from a standing start. If I plant my feet - it barely 'fights back'. It gets up to about 2 km/h on WOT and revs really high. I work around this by jogging it along until about 10 km/h, which is about the speed it needs for the clutch to engage (I assume that's what happening). Once engaged, it cruises up to about 30 km/h and runs reasonably well besides four-stroking at certain speeds/throttle. I checked the carb, and can't find anything obviously wrong there - jet is clean etc.

Could this be an air leak, or is this most definitely a clutch-related issue? Air leaks call for new gaskets, but how would I go about diagnosing the clutch? Any and all suggestions are much appreciated.

PuchMaxi.jpg

Re: Puch Maxi acceleration problems

First check and see if the brakes are sticking by turning the wheels by hand on the stand...

Re: Puch Maxi acceleration problems

> Bob Selby Wrote:

> -------------------------------------------------------

> First check and see if the brakes are sticking by turning the wheels by

> hand on the stand...

I checked that, brakes were fine. I'm pretty sure it's a engine-related issue. When I plant my feet and 'challenge' the bike to accelerate, the engine eventually gives up - rpm goes down and it eventually dies.

Re: Puch Maxi acceleration problems

Methinks your jetting is F'd up. Like somebody put too big a jet in, or drilled it out. Sounds like you're drowning it in gas.(edited)

Re: Puch Maxi acceleration problems

As far as I can tell - I’ve got a 16mm carb with a 56 jet, which doesn’t sound very large to me?

737E8CA6-6559-4BBA-8B4F-A6BC1234037D.jpeg
8A153A9C-9FCE-4EF8-8CC3-5EF40E0D3ABD.jpeg

Re: Puch Maxi acceleration problems

The carb size is stamped on the opposite side of the carb in your picture.

If you're running the stock carb, cylinder, and pipe, and you've already cleaned the carb, then you may have worn out clutch pads that aren't able to grab until the RPMs are high enough and might be slipping due to lack of friction material. Should probably open it up and have a look.

Re: Puch Maxi acceleration problems

> J H Wrote:

> -------------------------------------------------------

> As far as I can tell - I’ve got a 16mm carb with a 56 jet, which doesn’t

> sound very large to me?

No, that doesn't seem too big. Still, someone may have drilled it larger. Maybe not. But I've had it happen to me. Post a video of what it's doing, if you can.

Re: Puch Maxi acceleration problems

> Mike Boyd Wrote:

> -------------------------------------------------------

> The carb size is stamped on the opposite side of the carb in your

> picture.

>

> If you're running the stock carb, cylinder, and pipe, and you've already

> cleaned the carb, then you may have worn out clutch pads that aren't

> able to grab until the RPMs are high enough and might be slipping due to

> lack of friction material. Should probably open it up and have a look.

Thanks!

The clutch pads are my number 1 suspect right now. Question: Does the moped's speed affect the clutch's engage-timing, or does it purely depend on rpm? I ask because the moped revs really high before it gains speed and the clutch engages.

Re: Puch Maxi acceleration problems

^^that makes more sense. It sounded to me that it was bogging. If you're revving high rpm's and not going anywhere, it's your clutch.

Re: Puch Maxi acceleration problems

Chöschi21 C.K. /

> J H Wrote:

> -------------------------------------------------------

> > Mike Boyd Wrote:

>

> > -------------------------------------------------------

>

> > The carb size is stamped on the opposite side of the carb in your

>

> > picture.

>

> >

>

> > If you're running the stock carb, cylinder, and pipe, and you've

> already

>

> > cleaned the carb, then you may have worn out clutch pads that aren't

>

> > able to grab until the RPMs are high enough and might be slipping due

> to

>

> > lack of friction material. Should probably open it up and have a look.

>

> Thanks!

>

> The clutch pads are my number 1 suspect right now. Question: Does the

> moped's speed affect the clutch's engage-timing, or does it purely

> depend on rpm? I ask because the moped revs really high before it gains

> speed and the clutch engages.

The cluch engages with the RPM's of the Crankshaft, but you probably are Pedaling it up to a speed were it can grab, the Difference in Rpm's between the Transmission and the Crankshaft is smaller and it can grab better.

Re: Puch Maxi acceleration problems

> Chöschi21 C.K. Wrote:

> -------------------------------------------------------

> > J H Wrote:

>

> > -------------------------------------------------------

>

> > > Mike Boyd Wrote:

>

> >

>

> > > -------------------------------------------------------

>

> >

>

> > > The carb size is stamped on the opposite side of the carb in your

>

> >

>

> > > picture.

>

> >

>

> > >

>

> >

>

> > > If you're running the stock carb, cylinder, and pipe, and you've

>

> > already

>

> >

>

> > > cleaned the carb, then you may have worn out clutch pads that aren't

>

> >

>

> > > able to grab until the RPMs are high enough and might be slipping

> due

>

> > to

>

> >

>

> > > lack of friction material. Should probably open it up and have a

> look.

>

> >

>

> > Thanks!

>

> >

>

> > The clutch pads are my number 1 suspect right now. Question: Does the

>

> > moped's speed affect the clutch's engage-timing, or does it purely

>

> > depend on rpm? I ask because the moped revs really high before it

> gains

>

> > speed and the clutch engages.

>

> The cluch engages with the RPM's of the Crankshaft, but you probably are

> Pedaling it up to a speed were it can grab, the Difference in Rpm's

> between the Transmission and the Crankshaft is smaller and it can grab

> better.

I see, thank you!

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account