Back fire

Yep, what @Owen Lucas said. I had such a bad luck on my rebuilt Kawasaki that I cut the plunger off. So long as you idle down the engine for a few it should not backfire.
 
While running, if you disconnect the wire from the solenoid on the bottom of the carb, it should stop immediately. If it does not there is a problem with the solenoid. The only purpose of that solenoid is to prevent "dieseling" and/or backfiring after shutoff.

Also when is the last time you checked / cleaned the cooling fins, as overheating can cause stuff like this.
 
I had a air cooled Kawasaki that would do that. I switched to premium gas and idled it a bit before shutting down to correct the problem.
 
Might want to check your spark plug(s) for signs the engine is running too lean. 100% agree about idling a while before shutdown to eliminate the backfiring.
 
Back
Top Bottom