ridin buddys 86 cr 125 broke tired of ridin alone

[kevf]

Would appreciate any ideas on what may be wrong with friends bike. He will start off and 1st and 2nd gear will be fine when he shifts into 3rd and attempts to open her up and run it through the gears it will break up and spitter and sputter. It has a new top/bottom end and to try to fix it he has replaced reeds,cleaned adjusted carb,new airfilter,cleaned adjusted ATAC valve. He is goin to replace Cdi next . When he adjusted carb he ran it through the gears on a car lift and it seemed to be alright but he rode it on the trails and it sputtered like it did before. It had this problem last year and it all of a sudden stopped sputtering and fixed its self. Any ideas would be appreciated. Thanks kevf

 

[motometal]

Did you try a new spark plug?

Could the gas be bad?

 

[A-RustyDemon]

Sounds like he may have water contaminated fuel in the float bowl. It only take a drop of water to cause the type of symptoms that your friend is having. Tell him to drain the bowl and put on a inline filter see if that cleans up his troubles.

 

[kevf]

he has tried changing plug and he cleaned carb and drained fuel.

 

[SterlingYZ]

That sounds like a jetting problem. He may have Cleaned the carb, but maybe he needs to go to a leaner jet. With a fresh top end, it can't be much else I would imagine. Either way, let us know what you find.

Good Luck - Sterling

 

[kevf]

i dont think it could be a jetting problem since it happened last year and it the problem went away by itself without fixing anything.

 

[Glitch]

I got an '87 CR125 and it was known to let water in through the flimsy plastic ignition side cover. This caused the flywheel to be wet and the bike ran like your friends. When I drained the ignition area, the bike ran great. This might be your friends problem but probably not. I also found that lowering the main jet size made the bike run tons better, this also worked on my friends '91 CR125, both our bikes fouled plugs like crazy, then lowerd main jet and ran like champs. Also, my bike doesnt seem to like to run good in the winter time, which is probably caused by the gas that I buy, because in the winter an oxyangenator(sp?) is added to all gas, making bike run richer, I think. So your friends bike could of cured itself when they stop putting that additive in the gas, usually in spring.

 

[bclapham]

Originally posted by kevf
i dont think it could be a jetting problem since it happened last year and it the problem went away by itself without fixing anything.

on the contrary my dear man! jetting changes with the weather. it could be spot on during a colder winters day, but when it warms up and yougo to some higher trails it will be really rich.

buy some jets and have fun, even if it doesnt help at least you can rule out another possibility

 

[kevf]

my buddy just called and he said he fixed it. he said the bike had a high and low end pickup he replaced the high end pickup and took it for a ride screamed like before thanks for the ideas. ride red.....kevf