Edited Date/Time:
So while I am working the 1986 YZ125 I also have this CR125. Both were dying in a back yard with no love.
When I first got her she was really crusty. Notice the electrical tape in place of the boots on the shocks...
We brought her home. Cleaned out the carburetor then then blew the carburetor out with compressed air. We changed the transmission oil and checked the radiator fluid. Then we put a new spark plug in and this happened:
CR125 comes alive!
Next we checked for the dreaded corrosion in the water pump area. It was full of corrosion thatvlooked like white toothpaste. After digging it all out and checking the water lines there appeared to be very little damage.
We replaced the water pump gasket and put it back together. Unfortunately the radiators were full of white corrosion sludge. It took them to a radiator shop and for $20 they were able to clear them out. We then filled the bike with Evans waterless coolant so hopefully corrossion will not be an issue in the future.
The screw in the throttle housing on was completely seized and we were unable to drill it out. So I got another one off eBay for $8 shipped.
I have been sanding the plastic to restore it so it is starting to look better. The back fender is not OEM and no amount of sanding will help it.
I painted the handlebars and added new grips and a new throttle cable.
The bike has good power but is on the lower compression end.
I have some questions:
1. I can get a new front and rear fender from UFO for $54. A new OEM front and rear fender from Partzilla is $90. Is it worth the difference in price. I ask that because I will also need new tires, case gasket (leaking a little oil), new sprockets, new shock boots, maybe new clutch plates, and new decals.
2. If the compression is low I assume I either have to get new rings or possibly a new piston and rings. If the cylinder wall is marred up can the bike be bored, plated, or is it sleeved? when examining how is all of this in #2 determined.
I would like to do a big shout out for my brother. None of this would have been possible without his help.
BTW I got both bikes for free. I think the previous owners had no more use for them. They were happy to get rid of them and happy that someone might save and use them.