Seized Puch Maxi Engine (Need Advice/Thoughts)

So here is the deal:

I just recently bought a Puch Maxi moped that wasn't running, in hopes that I could fix it up and learn a thing or two in the process. This is my first ped and I am not very savy working on bikes at all. Anyway after a little troubleshooting I am pretty sure that the problem is a seized engine, but let me tell you what problem I am having.

The bike will roll just fine and I can use it by pedaling as if it were a normal bike, but when I pull down the clutch and try to give it a kick to start it, the pedal wont budge. it seems like a classic case of a seized engine.

The bike had been sitting in a garage for at least a year without being run, so that is another reason why it would make sense for this to be a seized engine. It also makes me believe that the seized engine was caused do to the engine not being run in a while as apposed to it being caused by using cheap oil or being run without oil.

Everything on the bike looks stock and i know that the bike has an E50 engine. From what little I know, it seems that the next step would be to try and manually unlodge the piston from the cylinder by soaking the piston in a high penetration lubricant for a while and then hitting a peg against the piston with a hammer in the hopes of freeing it. Do I have that right?

My questions are:

1. How do I go about doing this?

2. Is this the right approach?

3. Does it sound like there is hope for this engine? Has anyone salvaged an engine that has been seized like this, and does it help if the reason for the seize is because of the engine not being run in a while as apposed to it have been run with a bad gas-oil mix, or does it not really make a difference what the cause of the seize was?

I am new to all of this and, unfortunately, do not know alot of the terminology or names of the parts, but I would really appreciate any help I can get and your thoughts.

If you need any more info from my end let me know, or if pictures will help I will upload some.

Thanks! (edited)

Re: Seized Puch Maxi Engine (Need Advice/Thoughts)

You have the right idea. It's probably not seized hard if it's just stuck from sitting. It's not uncommon, nor particularly hard to fix. Let it soak for a while.

Re: Seized Puch Maxi Engine (Need Advice/Thoughts)

Gotcha, can do. I just picked up some P'Blaster so that will hopefully do the trick.

Re: Seized Puch Maxi Engine (Need Advice/Thoughts)

Welcome to mopeds. You're in luck having one of the easiest transmissions to work with (the E50)!

I would try getting a socket on the flywheel nut like you're going to pull it. Sometimes it will turn over and break the piston or crank free if stuck.

Re: Seized Puch Maxi Engine (Need Advice/Thoughts)

Thanks, I appreciate the welcome. Ok It's dark out over here, but I'll give that a try tomorrow and let you know how it goes.

Thanks a ton for the suggestion. It really helps.

Re: Seized Puch Maxi Engine (Need Advice/Thoughts)

Got it fixed guys.

A little PBlaster in the cylinder allowed me to rotate the piston using the flywheel. The cylinder seemed to be in great condition as far as I could tell there was no scoring whatsoever, but then again I don't exactly have a trained eye for that sort of thing.

I would say that it definitely seized due to not being used, because it was not hard to unseize at all once I put PBlaster in there.

Is there anything else I need to do to make sure everything is working properly?

Thanks for all your help guys!

Re: Seized Puch Maxi Engine (Need Advice/Thoughts)

Moped Lar (OFMC) /

Even though you unstuck the piston from the jug, the rings could still have seized to the piston. Make sure the rings are loose and compressible.

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