1989 yz 125 bottom end

SRAD97750

SRAD97750

Moderator
Staff member
Wow, that's crazy expensive to not be guaranteed a good bottom end afterward. The used one could lock up first ride!

I posted links before to the parts you need to do the bottom end. Total with machine shop costs and tooling is ~$200
WAY less than $329 spent on a total gamble.

SRAD97750:
Might be cheaper just to rebuild the bottom end. $108
Bearing/seal kit
http://www.ebay.com/itm/Main-Crank-Shaft-Bearings-and-Seals-Kit-Yamaha-YZ125-1986-1987-1988-1989-1990-/251168409285?pt=Motorcycles_Parts_Accessories&fits=Model:YZ125&hash=item3a7acdc6c5&vxp=mtr

Connecting rod kit. You'll have to take the crank and kit to a shop.
http://www.ebay.com/itm/YAMAHA-YZ12...Parts_Accessories&hash=item23180cb8c3&vxp=mtr

-BIG DAN:thumb:
Click to expand...
 
SRAD97750

SRAD97750

Moderator
Staff member
A crank bearing/seal replacement job typically runs 4 hours if the engine is out of the bike.
I think I quoted roughly $108 in parts.
My local engine shop charges around $50 for crank overhaul labor.
Most likely under $300 + Shipping at Big Dan's Motorcycle Maintenance

Or you could do it yourself for ~$200 and gain experience.
-BIG DAN:thumb:
 
O

ossagp

It is a pretty simple engine. i have a batch of yz 125's from the 94-2004 era. never needed a case splitter though i have some. you can easily make one from a harmonic balancer/steering wheel puller though.

getting the crank out is pretty easy. if it wont lift out it will come out bearings and all with a little bit of heat applied to the cases via a propane torch or heat gun. oven works too with lots of drawbacks if you have a significant other or mother.

just photo as you go and at least have an exploded view of the parts.

get the press and alignment work by someone who does lots of them. if you have a press and lots of time I will tell you how I do it though.

Dan's price would have me out of the DIY business if he was closer.
 
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