Blew engine, and other questions

So I did my first moped rebuild and it was fun and turned out good. So I thought. It rode for about 2 days then I started to noticed a violent shaking when entering 2nd gear but just assumed it was slipping. About a hour later I look down and there's a hole in the bottom of my engine. So I rode it home with barley and transmission fluid in it and tore the engine apart. Apparently one of the bearings on the clutch cover broke and got sucked into the engine causing it to get stuck in the main gear which cracked my left side crank case. I also noticed some other problems. My clutch spring holder kept popping out cause it to scrape against the clutch holder or bell and also my gears had a little play to them also my crank shaft had a tiny bit of side play. Also my piston had alot of carbon on it from a very short time of riding. I'll add some pictures if anyone has any idea of what to do. I'm already about to order the left side crank case from treats. Should I get anything else?


Re: Blew engine, and other questions

These are some more images also my second gear would take like 10 seconds to shift when WOT


Re: Blew engine, and other questions

hard to tell, kinda large, but isn't that a vent hole?

stuff to get, countershaft bearing, gaskets, countershaft shim, clutch retaining springs, seals, sprag spring, bearings

Re: Blew engine, and other questions

Beach Club Nick /

I don't see the hole you're talking about in those pictures, not sure if cause they're not very good or cause there isn't anything out of the ordinary

Re: Blew engine, and other questions

You should use a matched set of case halves if possible. Used A35 cases are cheap and easy to find.

Re: Blew engine, and other questions

Are you thinking the drain hole that goes from the cavity under the carb down into the area behind the stator is a hole in your case? Definitely not. All the other symptoms you are describing could be caused by that bad bearing. I would just clean things up, replace both cover bearings and the crank bearings and seals, and rebuild with new gaskets.

If I had to guess you forgot to refill it with oil or it leaked out the drain bolt somehow or you fucked up a gasket/ mating surface and the oil loss caused the bearing to blow.

If I get a chance this afternoon I can maybe take a pic of that drain hole, it don't go anywhere near the parts of the engine that hold oil.

Re: Blew engine, and other questions

I'm sorry I think I forgot to take a pic of the hole in the engine. It was a clear crack that all the fluid drained out. A bearing got caught in a gear and cracked right through the case.

Re: Blew engine, and other questions

Unforget ; go take and post that pic . :)

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