Small Engine Troubleshooting Problems? Ask a Mechanic Now.
What is the engine make and model? Twin engine I assume. Do a cylinder balance test. Loosen the spark plug wires, and with the engine idling, remove one wire at a time. If engine dies when wire is removed, the opposite cylinder is not firing. Check dead cylinder for spark. If it has spark, check compression.
I suspect engine is running on one cylinder.
I suspect it has a bad coil and would be easily replaced , held on with two bolts, next to the flywheel. I doubt it is cylinder problem.
Do cylinder test when engine is acting up, hot.
Coil may not break down until hot!
OK> let me know.