1987 cr125 very strange kick and noises

Second post about this bike and still don't know what totally wrong. Bike has problems starting and running. Bogs down and cuts out sometimes. Very temperamental. Rebuilt the top end and has less than an hour on it. First time trying to start it ended up having to pull start it. After that she was running well enough. Flash forward about 4 days and I can't start it again. I kick it and she will sputter and die immediately after. We do know the carb needs rebuilt, but this is when stuff gets weird. Had my friend pull me on his quad and she starts popping but when I give it throttle she just bogs down and dies. We keeps going and I give her a bunch of throttle and she doesn't die. We stop and we untie it all and I kick her and she starts. Take her down a couple feet and turn her around and she dies AGAIN. Kick her and nothing. Again and again nothing. I finally give in a kick her full throttle and she starts. Me being a dumbass and a couple houses down the road from home I ride her home like that (giving it breaks between shifting) I let off the throttle and pull in the clutch and she bogs when I chop the throttle then dies. I was going fast enough to bump start so I drop the clutch and the tire locks up. Pull it back in and cruise to a stop. Hoping for the best I kicked her and the kick was WAY different then it was before that. Compression is harder and sounds deeper. I don't know what happened so I just put her away and go inside for night. PLEASE REMEBER that it has less that 30 minutes on the top end

UPDATE: when I take the plug out and kick it, she kicks like normal. But when the plug is in it kicks strange. Decided to yolo it and throw a new plug in and try to start it. Kicked it over 150 times, and got nothing but a very odd "puff" of air sound a couple times. Like a weak back fire and a smell of burning gas and oil. When I kick it she sometimes kinks and I hear a clicking noise. Never had anything like this happen to me in my life nor have I heard of something like this. Could something have wiggled loose under the vibrations? why is the problem only seeming to ensue while the plug is in? Please help. To me only way I can really describe the kick now is as if it's almost restricted, or it isn't exhausting the air out of the exhaust port. The kick also seems like it is off time. And isn't getting a full cycle in.

did you install the piston backwards

I'd check the carb. Give it a good cleaning. Jet it to factory specs check the needle clip position. Float height etc. what kind of shape is the reeds in? Like mentioned above did u install the piston backwards? Also with a bike that old I'd definitely check for leaking crank seals. Make sure the gearbox isn't over full on oil.

I'd check the carb. Give it a good cleaning. Jet it to factory specs check the needle clip position. Float height etc. what kind of shape is the reeds in? Like mentioned above did u install the piston backwards? Also with a bike that old I'd definitely check for leaking crank seals. Make sure the gearbox isn't over full on oil.

I changed the oil so it should be fine on that part. Reeds are in good condition, no cracking or broken pieces. I'll have a good look tomorrow at the carb again and hope for the best. I don't know if it is in backwards or not because my dad rebuilt the bike for me and surprised me with it on my birthday. He says he installed it with the arrow facing forward so I'm trusting him.

Wish ya the best man

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now