Puch Maxi Won’t Start

I have a 1981 Puch Maxi Sport that I recently stripped and repainted. Since reassembly I cannot get to run to save my life! It was hard to start prior to disassembly but ran great once started.

I’ve been through the forums, educated myself of spark, timing, etc and still no luck. 3 loaded tacos and a 6 pack of Corona will be overnighted to whoever can help make this SOB start!

1981 Puch Maxi Sport

- e50 engine with DMP 70cc kit installed by previous owner

- Gas tank was rusty so I POR 15 cleaned and sealed the tank

- Carb disassembled, cleaned, new seals, and running a #80 jet. New fuel filter and spills over gas when primed so I know it’s getting fuel

- New NGK B7HS plug. Has good spark

- Compression tested at 120 psi

- Found TDC using piston stop. Set point gap using a piece off a cereal box. Set timing to 15 degrees advanced

- Confirmed wiring is correct per service manual

The engine turns over but will not start. Tried removing the carb and using starter fluid. Started 2x that way but wouldn’t stay running. Has not started since.

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Re: Puch Maxi Won’t Start

More photos for reference

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Re: Puch Maxi Won’t Start

Is the slide on your carb stuck at all? If its stuck open that could pose a problem.

Re: Puch Maxi Won’t Start

Good thought. The slide is working properly. Just replaced the throttle cable and housing too.

Re: Puch Maxi Won’t Start

> Ed Kirsch Wrote:

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

> Good thought. The slide is working properly. Just replaced the throttle

> cable and housing too.

I know when I put on my vm20 the cable was alittle short so the slide stuck open on it....took me a few mins of brain scratching to figure that out..lol(edited)

Re: Puch Maxi Won’t Start

Do you know you have gas coming into the Cylinder? IE wet plug?

The plug may be grounding out on the cylinder once you screw it back in. You can check this with a timing light. Maybe the plug boot or wire is grounding out something?

Could also be bad bearing seals....:(

Re: Puch Maxi Won’t Start

Ive also read were you can have spark but a bad CDI....maybe thats why it was being a pain before?

Re: Puch Maxi Won’t Start

Yes, pulled the plug after trying to start several times and it was wet.

How would I check if the plug bolt or wire is grounding something out?

Any way to check for bad seals?

Re: Puch Maxi Won’t Start

the point just crack open at 15degrees correct?

Re: Puch Maxi Won’t Start

Actually the points are closing at 15 degrees. They are open up until I rotate clockwise to 15 degrees

Re: Puch Maxi Won’t Start

How do I check if the CDI is bad? Any tutorials out there?

Re: Puch Maxi Won’t Start

Your bike has points, not CDI.

Re: Puch Maxi Won’t Start

Can you verify your timing with a light? Is the flywheel installed on the key? Maybe actually sparking after tdc.

Re: Puch Maxi Won’t Start

The spark is sent the moment the points open not close

Re: Puch Maxi Won’t Start

> Ed Kirsch Wrote:

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

> Actually the points are closing at 15 degrees. They are open up until I

> rotate clockwise to 15 degrees

backwards man, u want em just to crack right as its hitting 15 btdc. im hungry, gimme my tacos n beer. points look a little compromised too.

Re: Puch Maxi Won’t Start

That is so strange because I never removed the stator/flywheel and it ran before I repainted it. Ran poorly, but ran.

So how do I get them to unreversed? Did the last owner install the flywheel upside down?

Re: Puch Maxi Won’t Start

If the flywheel wasn't torqued down properly it is possible it slipped. Without having done it yourself there is no way of knowing what went on before. Even if it was installed on the key, the key is made from very soft metal to shear rather than cause crankshaft damage. The taper of the crank and proper torque on the nut hold it in place. Use your piston stop to loosen the nut and if you have a puller take off the flywheel noting its orientation to the keyway when you pull it off. If you don't have a puller leave the nut on the end of the crank threads and tap lightly with a hammer while pulling, the nut is to save the threads. I've had success with this method on push mowers. Remember tap lightly, the vibrations will loosen it. Reinstall the flywheel with the keyway. And start it up. If it starts Then recheck the timing.

Re: Puch Maxi Won’t Start

Jared Rut you are the frickin man! She’s alive!!!

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Re: Puch Maxi Won’t Start

Well she’s not running again :(

It started with one kick after I installed the flywheel properly but won’t start again... I pulled the flywheel back off to make sure that it didn’t slip off the key again but it was still in place.

The felt pad inside it pretty worn down and I have some marring on the inside face of the flywheel. Is that enough for it not to start? I greased up the flywheel cam on the inside where the felt and point lie against it, reinstalled the flywheel, and still nothing.

Now I’m wondering if my stator and points is too worn down or if the ignition coil is going bad?

Re: Puch Maxi Won’t Start

Pushrod Fifty /

Try using an analog multimeter buzzer attached to the coil wire and ground and adjust timing so the buzz stops or reduces in sound level when the points open at your flywheel line to the right. Adjust the points within the gap range to get it or move the stator plate. Tighten the 3 stator plate screws and points screw and check again.

Re: Puch Maxi Won’t Start

Hey All - here are some photos of the flywheel off. Do any of these parts looks worn or damaged enough to cause the bike not to start?

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Re: Puch Maxi Won’t Start

The points are also opening up at 45 degrees for some reason. Here’s a video of what’s going on.

Re: Puch Maxi Won’t Start

Barack Obama /

> Ed Kirsch Wrote:

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

> The points are also opening up at 45 degrees for some reason. Here’s a

> video of what’s going on.

>

>

Go buy a timing light! And use a drill to find out where the firing Mark is...end of story

Re: Puch Maxi Won’t Start

Pushrod Fifty /

Condenser looks original. I would replace it. I think there is a service manual download in the wiki.

Re: Puch Maxi Won’t Start

look up timing a puch on youtube it will give u a visual of what to do and what to look for. that coil shouldnt touch the flywheel, it posibbly slid out? adjust w screws, and clean clean clean, or maybe something got caught up in there or your flywheel wobbling, theres a wiki on lapping your taper for a tight fit.

Re: Puch Maxi Won’t Start

Mark tdc on opposite side of flywheel. Your marks are at bdc and you're seeing the points closing. Find true tdc. Adjust timing. Set point gap when just past tdc and fire her up!

Re: Puch Maxi Won’t Start

Seems like the magneto is moving around.

Pm me if that's the case

You'll oull need blue loctite and valve grinding compound....

Thats after i mated the surfaces with grinding compound for about 15 min.

Then i cleaned the shaft w ether.

Blue loctite. Wait 1 hour

Brapp

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