Posts
532
Joined
11/23/2018
Location
Evans, GA
US
Brian_Bowles
12/31/2018 12:05pm
12/31/2018 12:05pm
Edited Date/Time
3/30/2020 6:52pm
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.
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.
The Shop
I hear people say you can spend so much on one of these and easily outspend the value of the bike. It makes it a lot better when you got the bikes for free.
So what about the piston. I figure I will check the compression tomorrow. When I first tested it the compression was at 110lbs. Now that was before it had been run and had sat for 5 years. I expect it would be a little higher now. I will say the previous owner told me how he rode the CR125 FOREVER EVERYWHERE when he in his teens. I asked him if he ever put rings in it and he said no. So my question is what am I looking for when I take the head off. I was thinking of the following:
1. Check for scaring on the cylinder wall. If there is no major scaring I can probably have it honed and get a new piston and rings.
2. Check for play in the crank. I know it will move side to side but should not move up and down. How much movement is ok?
Should I take the ring off and put it in the cylinder and measure the gap with a feeler gauge?
Pit Row
Go with the UFO plastics. They do everything apart from the side panels. (87 rad scoops are the same as the 86) The UFO plastics are actually a better colour match than the OEM ones you can get! (Yes, really) The mix must have been changed slightly over time and the OEM fenders are a little bit pink. It's quite noticeable when they are next to original "orange" side panels. The UFO stuff is spot on for colour and fits perfectly, it's also cheap!!
Stevie
I took the rear shock off today. That was easy. The bolt that holds the swing arm on was another story. I think I will have to get a longer tool with more leverage to get the bolt unscrewed.
Post a reply to: 1986 CR125 alive again! she is done!