Just as in a car, to ensure your boat's outboard engine fires correctly, you must have clean, working spark plugs. If you don't, this can result in poor gas mileage, lowered engine performance, and a shortened life for your engine. While it is recommended to replace your spark plugs, cleaning them is a viable option if you cannot replace them.
Remove the spark plug wires by twisting them off the spark plugs, then take out the spark plugs with a ratchet.
Visually inspect each spark plug's case for cracks or breaks. If you find any cracks or breaks, replace that spark plug or you will risk damaging your engine.
Scrub each dirty spark plug with a dry wire brush until you have removed the majority of the rust and accumulated grime.
Spray the spark plug with brake cleaner to ensure no debris is left in the threads or on the casing.
Replace the spark plugs in your engine.
