How to Troubleshoot an 18 HP Kohler Small Engine

Find the 18 HP Kohler small engine's spark plug on the right side of the motor. A thin black ignition wire lies nearby and should connect into the spark plug. If disconnected, reconnect it by inserting the wire back into the rear of the plug.

Replace the spark plug if there's any visible brown or white corrosion on its end, or if the engine will not turn over and start. Disconnect the ignition wire from the rear of the old plug and pull it out, then reconnect the ignition wire to the rear of a new spark plug.

Find the two terminal wires on the machine's battery. There's a red (positive) terminal wire and a black (negative) terminal wire coming out of opposite sides of the battery. Trace these back to the solenoid on the Kohler small engine. Both wires should connect onto bolts on the side of the engine's solenoid.

Reconnect either or both terminal wires to the Kohler small engine's solenoid by placing the wire's end over the solenoid's bolt(s) and tightening the wire onto the bolt(s) using a socket wrench.

Find the carburetor bowl. This easily identifiable bowl is about halfway up the left side of the 18 HP Kohler small engine. A sputtering or inconsistent engine is likely the result of the carburetor being filled with fuel and liquid. Place a dish under the nut on the underside of the Kohler's carburetor bowl.

Loosen the carburetor's nut with your socket wrench to drain the bowl's excess liquid into the dish.

Tighten the nut back up within the bowl with your wrench once draining has completed.