NGK BP8HS-10 SPARK PLUG

Function and technical context

The NGK BP8HS-10 spark plug is the ignition element responsible for generating the electrical spark that ignites the air-fuel mixture inside the combustion chamber of the petrol outboard or inboard engine. It is part of the ignition system and works closely with the high-voltage winding, the distributor and the CDI or electronic ignition module. A bad spark plug produces incomplete or irregular combustion, which results in difficult starts, jerks while cruising and noticeably higher fuel consumption. If the failure is total, the affected cylinder stops working, causing excessive vibration, severe loss of power and possible damage to the catalyst or the piston itself due to knocking. The reference BP8HS-10 indicates a thermal grade 8 with a standard electrode and electrode separation of 1.0 mm, parameters that make it suitable for engines with specific work regimes where controlled heat extraction is required.

When to replace this part?

The most common symptoms of a worn spark plug include costly or repeated cold starts, rough idling (especially noticeable in multi-cylinder engines when one of the cylinders misfires), choppy acceleration, and increased petrol consumption. In marine engines for recreational use, it is recommended to inspect the spark plugs during each seasonal maintenance and replace them every 100 hours of operation or at least once a year, following the engine manufacturer's instructions. Changing the spark plugs preventively before each season is one of the most economical interventions in nautical maintenance and avoids being left without starting or with reduced power at sea.

Compatibility table