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darren250r
10-01-2007, 09:28 AM
I have redone the bottom end on several 250r's, but I'm not familiar with the 2000 LT80 that I'm helping my friend fix. The clutch that attaches to the crank came apart and stripped the splines off the end of the crank.

We have the motor pulled apart and I have a couple questions before I proceed. The crank is in the right case half right now. Is the crank pressed into the right crank bearing? If so, I would assume that it needs to be pressed out and the new crank would have to be installed with a tool that pulls the crank into the bearing from the outside of the case, is that right? Also, since just the left side of the crank is bad, my buddy wants to just order the left half of the crank, press the crank apart and just replace the left side, is that a bad idea? Should he just order the whole crank?

Thanks,
Darren

LT80
10-01-2007, 05:04 PM
I recommend getting a whole new crank. Mostly because the LT80 cranks are thin where the rod end is compared to a 250R crank, thus it is very hard to get them straight.
I watched a guy do a 250R crank in literally minutes. I then watched him mess with a LT's crank for a hour. Nuff said.

I use a fine sand paper and sand where the bearing sits on the crank till the bearing slips on tightly (both sides).
Also sand/clean the guide dowels so the cases can slip right together.
You will need to use heat to assemble. I use a woodstove. Charcoal works well also. I don't recommend a torh unless your skilled enough as to not "all of a sudden" melt a case half. Aluminum ya know. :D
Stick a bearing on the left/clutch side of the crank. Heat the left case half and slide the crank/bearing right in. Stand it straight up and let cool.
Coat center with yamabond,,honda bond,,etc. (that greay thick stuff)..
Do the same for the right side. Tap the right case half down using light taps. It should slide right together.
Tighten the bolts and your done. No real torque setting,,
Crank should spin freely.
When all is cool, the seals can be pushed in. Lube the seal where it contacts the crank.

Nothing is really pressed..it just seems that way comming apart.
I just hit the crank till it comes out. heat can be used .
Hope that helps. :)