XR500 Black Fluffy Plug

[juice_bruce]

The spark plug on my XR500 gets carboned up very quickly.
I've cleaned and gone through the carb twice, all settings are stock.
Pull and test the plug, it appears to be a nice spark.
What happens is...
I start her, about a dozen kicks, best without the choke!
Then she'll idle nice and smooth.
I'll go for a ride and around mid to higher RPMs she, boggs, chokes and surges!
Pull the plug and it's carboned up.
I'm thinking electrical problem, any idea's?
Thanks,
Bruce

 

[2strokerfun]

I'm thinking fuel-related. Are you using fresh gas and new plug?? Checked valve clearance??

 

[juice_bruce]

Yes, fresh gas, new plug, checked valves.

 

[ZOMBIE666]

have you checked to make sure the choke is seating properly and sealing?

 

[juice_bruce]

Zombie666,
Good call, the choke works perfectly at the carb and the cable moves smoothly...but when you pull the cable then push it off the choke remains about 1/3 on!
I still have some issues, but the plug isn't carboned up.
I'm going to tweek the carb and she how it goes. Will post more info soon.
Thanks