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Old 10-14-2008, 09:54 PM
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jburr36 jburr36 is offline
Motorized Bicycle Elite Member
Join Date: Jul 2008
Location: Idaho
Posts: 284
Default 900 mile teardown report...

Ok. Summer's over and I want to be ready for next year. I hate surprises so I had an itch to see what kind of wear 900 miles did to these cheap engines to get a heads up on any problems that may arise. So I took my 80cc apart and stripped the paint and degreased all the parts. I repainted the parts that needed painted and closely inspected the critical parts.

Here's what I found.

* The cylinder has slight vertical scratches but it didn't affect performance.
* Lots of carbon build up. Removed carbon and all seems ok there.
* Bearings on clutch shaft had translucent vaseline or something. Also one had some metal flakes inside the bearing that gave it a gritty feel. I sprayed some WD-40 to clean it out and repacked both bearings. Seems okay now.
* The clutch plate and friction wheel has ball bearings that had no oil or grease. There are 3 holes that access the ball bearings in the back of the clutch plate. I shot some grease in there being careful not to put too much. The clutch pads won't work well with grease on them.
* at close inspection of the bottom of the cylinder I noticed a peice that look liked it was cracked however it is a casting problem (see pic). It hasn't been an issue so far so I'm not going to worry about it.
* Cylinder head has some real cashing issues. It looks like some severe cracking but it is bad cashing. No cracks, just looks ugly (see Pic).
* Piston looks absolutely fantastic for 900 miles after I cleaned the carbon off.
* Needle bearings look great and so do the main crankshaft bearings.
* Replacing all the screws and washers with stainless steel due to the climate here.
* Yes, That's why I painted my magneto green and the magneto rotor vivid purple.

Now it's time to reassemble the motor. I'm thinking of electroplating a new motor I might get instead of painting it.

Time to get to work.

P.S. That starter motor will work nicely once I maching the parts to make it fit. Will take some time for that though.
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