NGK BPR7ES-11 SPARK PLUG

Function and technical context

The NGK BPR7ES-11 spark plug is the component responsible for generating the electrical spark that ignites the air-fuel mixture in each cylinder of the marine combustion engine. It works directly in the ignition system, subjected to continuous cycles of high voltage, pressure and extreme temperature within the combustion chamber. A worn electrode or an incorrect gap causes intermittent misfires, a notable loss of power, increased fuel consumption and difficulties in starting, symptoms that on the high seas can compromise the safety of the boat. The reference BPR7ES-11 incorporates the designation "11" which indicates an air gap of 1.1 mm preset at the factory, which facilitates installation and ensures optimal combustion from the first moment.

When to replace this part?

The most common symptoms of a bad spark plug are: difficult starting or the need for several attempts, jerks and backfires at full load, high fuel consumption without apparent cause and irregular or unstable idle. As a general rule of preventive maintenance on outboard and stationary nautical engines, it is recommended to replace the spark plugs every season or every 100 hours of operation, whichever comes first, especially on intensively used two-stroke and four-stroke engines. Changing the spark plugs preventively at the beginning of the season is the most economical measure to avoid an ignition failure while sailing.