Fixing up a 97 CR125

I bought a basket case of a CR125 this past summer.  Once I got it home and tore it apart, I found that the lower bearing had gone.  The crank was wrecked and the top end was a mess too.  The cylinder and piston were toast and the head was all dented up from crank bearing pieces flying around.  The bike overall was in OK to less than OK shape so I debated fixing it up or parting it out.  I was leaning toward parting it out and replacing it with a running bike but for whatever reason I decided to rebuild it. 


Here is what I have done so far:


I started by completely rebuilding the bottom end - new crank and all new bearings.  The PO had just put a new wiseco clutch in it and everything else looked OK.

I sent the top end off to Eric Gorr to have him do a 144 big bore on it.

I stripped the frame, wheels, and hubs and had them powdercoated

Rebuilt the forks

laced up new spokes

rebuilt the carb

put in new reeds and new RAD valve boot

All new bearings - both wheels, swingarm, neck, and pivot


Here is what I still have to do:


Finish rebuilding the shock (disassembled and waiting on parts)

Put on tires

purchase and install new chain

purchase and install new radiator

purchase graphics

clean up or replace plastics and seat


I'm hoping to have it done by the end of April.  This bike is going to be my play bike/buddy bike.  I'm excited to see how the 144 does.









Edited by nucular

Nice! Looking forward to the finished product. To get to a 144 are you boring it the whole way +4mm I think? Or stroking and boring?

Just bored - using the 125 crank.

Nice looking forward to hearing a report.. Not sure what I wana do with my 125 yet. By the way I like the yz400 in the background very clean bike!

Thanks.  I like the 400 but I still need to sort out the jetting.  I have a handful of jets to try out if the weather will ever cooperate.  If I keep it, I am going to have to send the suspension off to someone to get worked over.  It's pretty terrible by today's standards.


Here is how that one started out:




And how it sits today:



Very nice.  I loved my 94.  I also had the 144 from eric gorr on it and it ran really well.  If you can get a PWK carb for it from the 00 cr250, you will love that. 

Tires on (MX52 rear, scorpion med-soft front), sorry looking bent radiators put on, brakes installed, and some other little stuff.  I would eventually like to put on new radiators and an oversize tank but that will probably be down the road.




Mylers does fantastic radiator repair.  Just has a set of rads done for my bro's 06 CR250.  Sent them in pretty smashed up, and came back looking almost new.

Thanks for the tip. What did it cost you?

Never mind I see the rates on their site. I was considering getting one of those eBay radiators for $125 or so. I thought the larger eBay radiator might help keep it cooler but I'm sure the quality isn't the same as oem.

The quality is definitely better with OEM. You also have the option to have bracing welded in. Sort of eliminates the need for rad guards or braces. That's what we did.

I think I will go that route then.  It will end up being a little cheaper too.


I rebuilt the rear shock - new seal, bumper, oil, etc.  I just took it to the shop to have them recharge the nitrogen.  I told them the bike it was for and that the manual listed 142 psi for the pressure but he said their mechanic said that it should be at 175 and charged it to that.  Does anyone know if that will matter?  :excuseme:

So close. Ordered new sprockets,chain,case saver,mounting brackets for the exhaust,bar pad, and a bunch of little stuff. I might actually be able to start it next weekend.


So close. Ordered new sprockets,chain,case saver,mounting brackets for the exhaust,bar pad, and a bunch of little stuff. I might actually be able to start it next weekend.



Looking really nice!!

Still waiting on the case saver but other than that and some brush guards, its done.  Hopefully try to run it this weekend.



That looks greeeeeaat!

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