Thoughts on this bottom end?

chuey_316

Member
Feb 9, 2010
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I recently bought an 01. Seller said that everything was there, but had no spark, and should run after diagnosing the problem. It came with 2 new adjustable stators, new kill switch, new coil, new voltage reg, new cdi, new off brand carb (yuk), 2 extra somewhat good harnesses, a few new plugs, 2 extra rear tires, new hood piece, and the tools to pull the flywheel for $400. Couldn't pass it up.

I installed all the new parts, rewired it from scratch, and got spark. The engine started, but barely ran. Come to find out, the piston dropped a skirt, and cracked open the bottom of the right crankcase.

Been searching for a replacement case, and came across this complete bottom end that I can pick up somewhat locally for $200. Only thing that worries me is the amount of oil/grease. Other than a cracked case, what would be the most likely cause, and what am I looking at to fix said problem(s)?

Honestly, I'm thinking that as long as the right side case is in good shape, I should buy it. Worst case is I end up using the crankcase with the engine I already have after cleaning it all out, and I'll have extra parts to either store away, or part out to someone who needs them.

I just don't want to spend another $200 and end up in the same situation as I'm in now with an unusable bottom end.

Also, what all should I check for when looking at it? Cracks are obvious. I know to check that it shifts through the gears, rotates freely in neutral, and to check for up/down play in the crank. Anything else?

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First off, how bad is your cases?

IMHO, no matter what you’ll probably be splitting cases.

The spare engine could be lack of maintenance (cleaning) or it could need all new seals. Considering it’s AT LEAST 15 years old what do you think?

Either go all in on fixing it right or sell it and move on. If your engine wasn’t already broken I’d suggest doing a compression test.
 
There's a chunk broken out from the bottom of the right side case. I picked up the replacement bottom end today. The cases are in great condition, trans shifts through all the gears smoothly, the cranks rotates free and smooth, and the crank bearings are good and tight, no up/down play. After I get the top end rebuilt I'll do a leak down test to see where I am with the bottom. I don't mind splitting the cases and replacing the seals if need be.
 
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