Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Black smoke? Too much fuel or too little air. Have you rana cylinder test, to be sure engine is running equal on both cylinders?
Loosen the spark plug wires and with engine idling, remove one wire at a time. If engine dies when either wire is removed, the opposite cylinder is not firing.
These twin engines run well on one cylinder, but have lack of power and can blow black smoke.??
Did you find the problem?