Question for all - Rebuilding 09 YZ450F bottom

Hi all, chain snapped and gashed my case, need to rebuild it. Getting the case (both sides) piston, rings, new clutch (basket maybe), top/bottom gasket kit, and the question is bearings and seals on the case. Besides the main crank bearings (2), what other bearings are needed? When I google the cases, they have several bearings on each side, but I am not sure which they are to order. Same with seals, the manual just says "seal" for all of them, no specific detail as to the name/part number etc. isn't much help, as the case pic's don't include the bearings.

Any help is apprciated

The bearing #s are in the parts list they are shown with the part they go with. I.E. the transmission bearings are with the transmission the balancer bearings with the balancer and so on. If the engine is in good shape otherwise and you are care full you can remove and reuse many of the bearings .

If it was me I would replace the bearings if your doing a rebuild

You might want to check out an aftermarket complete gasket and seal kit. I have used a Pro X before and it saved some $ over buying gaskets and seals individually. Other than the positive reviews on the website where I purchased them, that is my only experience with them.

You can get the Yamaha bottom end kit for $65 and it comes with all the seals and gaskets.

And if you want a good billet clutch basket you can get a performance engineering basket for $129.

Edited by trandyd

On my 2006 YZ450 F I had to replace the case halves, the biggest expense was the counter shaft bearings, OEM $55.00 each, after that I replaced all bearings, seals which I got from a local bearing house and gaskets came from Ebay. Good luck

I have parts you need. Mint bottom end under 20 hours. Shoot me a pm.

Would that plastic case save from TM Designworks stop a chain from breaking the clutch actuator arm?

I kind of doubt it, but if it came off gracefully enough, it might help. Better to use a real quality chain and adjust it right. People tend to run the chain tight on YZ's because they look loose when correctly set.

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