Honda CR60 plug fouling often

[Gottadiesel]

I am having an issue with my son's bike that we bought a couple of months ago. It is an 83 CR60 and feels like it has been modified - it appears to have been raced and is pretty fast, even with me on it. But it is fouling on the cool down, meaning that it will be running fine and then will not start at all until I change the plug. This is happening about every 2-4 hrs of riding. I have told him to try and run it a little harder, especially before shut down, but doesn't seem to matter.

Any and all recommendations would be appreciated.

Thanks Charles

 

[spaz5972]

Fouled plug

i got my son a Honda Cr60 and you are right they are fast. I had to go with a hotter plug witch is a BR8ES try that and see what happens

 

[SHSPVR]

I try lower the main jet needle you may need to even install a smaller main jet.
One way to get a round plug fouling is uesd Lucas Semi-Synthetic 2-Cycle High Temp Racing Oil.