Bottom End Rebuild Shenanigans...

DerSpezialist

New Member
Mar 13, 2018
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Hey guys,

I'm going to preface this by saying I'm a newb when it comes to rebuilds. But I'm determined to get this thing running again!

I recently acquired a 00 blaster. After noticing it will shift up and down and never stop, (i.e you are in 1st gear, press down 7 times on the shifter, you are then in 2nd gear...) My friend and I decided to investigate. We removed the clutch cover and noticed the shift drum shaft was broken off at the keyway. We figured we needed a new shift drum (and possibly forks) so we dropped the engine and began disassembly. After removing the top end and all outside covers, the next step was the flywheel and then split the case to get the drum out. Well, the damn crankshaft was STRIPPED. Some moron stripped the nut while putting it back on at some point and the threads were gone. We know engine work was done recently because it was bored out and there were etchings on the top end from 2016. So much for an easy fix...

All of you motorheads, We need help. Should we replace just the crank and drum, or the entire bottom end? Or has anyone had luck rethreading the crankshaft and just throwing on a smaller diameter nut? This project (thanks to the wife) has a tight budget, so I'd hate to spend all of the money in one shot and not have anything left over for any other issues.

Any help would be greatly appreciated!!
 
I use a harmonic balancer puller from harbor freight to split the cases, if you haven't already.
https://www.harborfreight.com/bolt-type-wheel-puller-set-62620.html

As to the crank , seems I've heard of this before. Don't recall the solution.
I'm very leary of used cranks, even if I could inspect it personally.
If you don't get more information give Ken O'CONNOR a call. He might have an idea/fix. Worst case get a used crank and have it rebuilt. Cheaper than whole new crank.