New user, first time poster. So, hello everyone and thank you for any help you might be able to throw my way!
I received a Yard Machines 20" push mower with the 300E series Briggs & Stratton engine that wouldn't start. I went over the obvious first. Fuel, oil, air filter, and spark plug. All looked well, so I gave the ol plastic carburetor a thorough cleaning. Primed the engine and it started right up, then almost immediately started surging. I went ahead and removed the carburetor and cleaned it once more. Same outcome.
I then:
Removed the gas tank and fuel line, flushed and cleaned. SAME OUTCOME. Always worth doing
Installed a new spark plug. SAME OUTCOME. Again worthwhile
Removed the coil and scuffed the flywheel and coil to ensure they were nice and clean. SAME OUTCOME. Total waste of time polishing the coil unless your are an idiot on U-Tube trying to sound intelligent. But cleaning the mounting posts for a good ground is
Swapped with a different carburetor. SAME OUTCOME. Points to something else
Swapped the coil. SAME OUTCOME. Surging has nothing to do with the sparking so waste of time
I'm at my wits end with this one and just cannot seem to figure it out. I need help.