NGK Spark Plug BPR7HS

Function and technical context

The NGK BPR7HS spark plug is the component responsible for generating the spark that initiates combustion in the outboard engine cylinder. It works directly in the ignition system, withstanding continuous cycles of high electrical voltage and extreme temperatures within the combustion chamber. A worn electrode or incorrect gap cause ignition failures, loss of power, increased fuel consumption and starting difficulties. The quality of ignition in each cycle is essential for the Yamaha engine to perform efficiently and reliably throughout the navigation day.

When to replace this part?

The most common symptoms of a deteriorated spark plug in an outboard engine are difficult cold starting, irregular vibrations at idle, jerking or power interruptions at medium and high load, and visible increase in fuel mixture consumption. In Yamaha outboard engines for recreational use it is recommended to inspect the spark plugs every 100 operating hours and replace them at most every 200 hours or at the beginning of each navigation season, depending on accumulated use. Preventively renewing spark plugs is one of the lowest cost interventions that prevents the most breakdowns at sea, especially in demanding navigation conditions.

Equivalent manufacturer references