How to Troubleshoot a Kohler 18 MV Engine

Attempt to start your Kohler 18 HP engine. If the engine does not turn over and never starts, remove your keys from the machine's ignition and open the hood covering the Kohler engine, if applicable.

Check the engine's spark plug. The plug can be found on the right side of the engine with a black ignition cable extending into its rear. The motor won't start if this cable is not secured onto the plug, so reinsert it into the plug's back if it has come loose.

Check the condition of the engine's spark plug if the engine still won't start. A spark plug in poor condition usually has either brown, black, or white corrosion on its end. Additionally, if the plug has a white band near its end, this band often becomes blistered with several black dots if the plug is faulty. Pull the ignition wire out of the existing spark plug if it exhibits any of these traits, and reinsert the wire into a fresh spark plug.

Find the solenoid on the engine. The solenoid can be found by tracing the battery's two terminal wires (red and black) back to it. Each wire comes to rest at opposite sides of the solenoid and should be fixed securely over each side's bolt.

Secure the terminal wires back over the solenoid's bolts if disconnected. Place each wire end over the bolt and tighten into place using a socket wrench.

Attempt to start your engine. It the engine starts but whines and sputters, either failing or on the verge of failing, this is probably a carburetor problem that can be diagnosed by checking for leakage. Find the carburetor bowl midway up the left side of the motor, then look on the bowl's bottom for a nut. Check if there is leakage from this nut. If there is, place a pan under it to catch the leakage.

Loosen the carburetor's nut with your socket wrench to drain the carburetor of its excess fluids. Wait for this process to finish, then retighten the nut.