Clogged Flame Arrestor/Air Box

Designed to stop flames from coming in contact with other fuel, flame arrestors help prevent a fire from breaking out. These devices can become clogged with carbon and debris, which will negatively affect the air/fuel mixture, resulting in no start/run rich situations. Remove the clogged flame arrestors and remove the debris using carb cleaner and a wire brush. Air boxes, especially those that are stored in non-marine environments, are susceptible to being clogged with debris such as animal nesting. Make sure the air box is free from debris prior to each startup.

Dirty or Clogged Fuel Filter

The fuel filter keeps dirt in the fuel from getting into the carburetor, and like the air filter, may eventually become clogged and prevent a sufficient amount of fuel from passing into the combustion chamber, preventing your engine from starting.

Faulty Spark Plug

A spark plug fouled by fuel, carbon, dirt or oil on the electrodes may not produce a spark strong enough to ignite the air/fuel mixture and start your engine in older two-stroke engines. Over time, deposits can build up on the spark plug’s center and side electrodes. This changes the gap of the spark plug and can short-circuit the electricity before it reaches the center electrode tip, weakening the spark.

Dead Battery

Leaving the radio, lights and pump on while anchored can run down your boat’s battery. If your boat has a two-battery system, forgetting to switch the battery before playing the radio or other accessories can run down both the house battery as well as the starting battery.

Old Gas

Ethanol-based gas can go stale in 30 days or less. Make sure the fuel tank contains fresh fuel, is properly connected and vented and there are no kinks or breaks in the fuel line.

Engine Not Primed

Make sure the engine is primed with fuel and choked properly at start if necessary.

Loose Spark Plug Wires

Improperly connected spark plug wires can make starting your engine difficult. Make certain all spark plug wires are properly connected and free of breaks. Also, check that the distributor cap and rotor are functioning properly.

Problems with Kill Switch

Check that the safety lanyard/kill switch is functioning properly and in the correct position.

Clean flame arrestor/air box.

Replace dirty or clogged fuel filter.

Replace fouled or dirty spark plug.

Switch to house battery when anchored and carry a jump starter.

Replace old gas with fresh gas (properly dispose of old gas).

Replace loose or damaged spark plug wires.

Test the kill switch to ensure its working and in the correct position.