CR 125 fouling plugs

[jakejake]

i have a 1991 HONDA CR 125 and i just rebuilt and bored the cylinder 40 over. it fouls plugs like crazy. once it runs. it runs excellent, once it is shut down, the following day it is hard to start. plug fouled with gas, replace plug and runs excellent, once it is warmed up and set to idle or driven slowly, and u go to punch the throttle it has a bog, if you rpull clutch in and hold throttle down, , it smokes alot and then cleans out and runs great again. what could possibly be wrong with it? any help would be great. thanks...

 

[wornknobby]

well first off remember you need to break in the "new rebuild". and i have found that when installing new rings the motor will run rich for some time and after the rings "settle" the richness goes away. check your spark to see if maybe it isn't enough, if so test your ignition coils to see if you have enough resitsance.

i know when i tested my kx for spark i thought it had enough to atleast light it but 200 ohms will make a BIG difference.

 

[Dragmeistr]

If you bored it .40 over would it not require some type of re-jetting due to the increased airflow?

 

[kevlt]

my 97 cr125 did this too, take the hp cover off and spray it out with wd40 once and a while. It works, I think that that year had the hp valve on the right side..... Well try it out, worked for me :ride: :cool:

 

[vasvar82]

Sounds like one of two things could be happening; either too rich mixture or inadequate spark. Is your air filter in a good condition? If all else fails, check your carb's fuel level