NGK UR4IX SPARK PLUG

Function and technical context

The NGK UR4IX spark plug is part of the engine's ignition system, being responsible for generating the electrical spark that ignites the air-fuel mixture in the combustion chamber in each engine cycle. Manufactured with high purity nickel electrode, it offers exceptional thermal insulation capacity that guarantees a consistent and powerful spark even under the demanding conditions of the marine environment: humidity, temperature variations and prolonged work regimes. Poor ignition caused by a bad spark plug directly translates into starting failures, jerks during navigation, increased fuel consumption and in serious cases, damage to the cylinder head due to incomplete combustion. Its correct selection and maintenance are therefore critical for the reliability of the outboard motor on any outing to the sea.

When to replace this part?

The most common symptoms of a damaged spark plug in an outboard engine are difficult starting or multiple attempts, rough idling, abnormal engine vibrations, and a noticeable loss of response when accelerating. In marine engines subjected to regular use, it is recommended to inspect the spark plugs during each seasonal maintenance and replace them approximately every 100 hours of operation or at least once a year, since the saline environment accelerates the corrosion of the electrode and the ceramic body. Changing the spark plugs preventively is one of the most economical and effective interventions to guarantee safe starts and avoid being immobilized at sea.

Equivalent manufacturer part numbers