I have pulled the spark plug and it is a light gray and actually looks pretty good.
Several things could make a carburetor backfire. The engine could be out of time. the carburetor could have a stuck float, or the engine could have a stuck valve.
Probably your float valve is stuck.
It is in the float chamber of the carburetor.
This is typically caused by a stuck or faulty float valve in the carburetor. Usually a good carburetor cleaning will take care of it. At the worst you will need to replace the carburetor.
Float probably stuck or has a hole in it allowing fuel to enter or Bad needle and seat valve
This is typically caused by a stuck or faulty float valve in the carburetor. Usually a good carburetor cleaning will take care of it. At the worst you will need to replace the carburetor.
If gas is coming out of the overflow tube on your CRF250R, it could be due to a stuck float in the carburetor. To fix this issue, try tapping lightly on the carburetor bowl to free up the float. If the problem persists, you may need to clean or replace the carburetor float valve.
Sounds like the fuel inlet valve is stuck shut, or the float isn't working properly.
The float and or the needle valve is stuck. Could also be rust or dirt in the needle valve keeping it open. try tapping the top front bowl of carb with a plastic mallet it free the float somtimes
The float could be stuck because of stuck needle valve, or rust. The float could also be leaking and be full of fuel.
It is probably a stuck needle valve for the float. Look under the carburetor for a round metal bowl with a bolt on the bottom. Unscrew the bolt and try to move the float up with your finger.
What if your float is not floating? Food for thought... If your float has gone bad then it wil not give enough force to close the Float Valve. Get a new float. If this does not fix it then the float valve you got is defective.