Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Run cylinder test! Loosen the spark plug wires, and with the engine idling, remove one wire at a time. Engine Should continue to run, if engine dies when wire is removed, the opposite cylinder is not firing. Check it for spark. (bad coil if no spark) check it for compression, and if it has spark and compression, check the valves.
Briggs twin engine can have pushrod off and run just fine on one cylinder. Let me know what you find. Thanks