The NGK AR6FS is an original standard spark plug developed for marine gasoline engines and particularly a range of older inboard engines. It is used in, among others, several classic MerCruiser, Volvo Penta, OMC, and Ford-based marine installations.
The AR6FS differs from many standard NGK spark plugs with its 18 mm thread and tapered seat. NGK specifies a thread length of 11.2 mm and a spark plug gap of 0.9 mm. The spark plug also features a built-in 5 kΩ resistor for suppressing electrical ignition noise.
NGK specifies the AR6FS for, among others, MerCruiser 255 MCM/MIE 350 cid from 1973-1980, Volvo Penta AQ190A, and various OMC- and Ford-based marine gasoline engines.
Always check the engine model, year, and manufacturer's specification before ordering, as the correct thread diameter, thread length, and sealing type are essential.
Key features
- Original NGK spark plug
- Developed for marine gasoline engines
- 18 mm thread
- Tapered sealing seat
- Built-in 5 kΩ resistor
- Nickel center electrode
- 1 ground electrode
- Electrode gap 0.9 mm
- Suitable for classic inboard engines
- Used for, e.g., MerCruiser and Volvo Penta
