Briggs popping

[outdoorpowermike]

From what I read you have a intake valve seat loose in the head, a bent or warped intake valve, or guide sliding out of the head.

 

[slomo]

Pull the valve cover and watch the valves move. Probably a push rod laying down on the job or a lean condition under high load. Lack of fuel delivery...... Do a leakdown test. Rocker arm loose.