NGK TR5IX IRIDIUM SPARK PLUG

Function and technical context

The iridium electrode of this spark plug acts directly in the ignition system of the marine engine, generating the spark that initiates the combustion of the air-fuel mixture in each engine cycle. Iridium technology provides significantly higher thermal conductivity and wear resistance than conventional copper or platinum electrodes, keeping electrode geometry virtually unchanged over thousands of hours of operation. In a marine environment, where saline humidity, temperature variations and long days at full load subject the ignition system to continuous demand, having a spark plug with an iridium electrode is key to avoiding ignition failures, power losses or irregular fuel consumption. Poor ignition during navigation can lead to unexpected stops at sea, abnormal vibrations in the engine and progressive damage to valves and pistons due to incomplete combustion.

When to replace this part?

The most common symptoms of a worn spark plug in a marine engine are difficult or irregular starts, jerks and loss of response in acceleration, high petrol consumption without apparent cause and unstable idle or engine cuts at low rpm. For iridium spark plugs, it is recommended to check the condition of the electrode during each seasonal maintenance and replace it according to the interval indicated by the engine manufacturer, generally between 100 and 200 hours of operation depending on the application. Replacing the spark plugs preventively before starting the sailing season is the best guarantee to avoid suffering an ignition failure far from the port.

Engine Compatibility

Equivalent manufacturer part numbers