The NGK BKR6ES (aka BKR6E-S) spark plug is a very common size used on a wide variety of small gasoline engines The BKR6ES is usually found on Johnson Outboard marine engines and Polaris ATVs Description The NGK BKR6ES (aka BKR6E-S) spark plug is a very common size used on a wide variety of small gasoline engines. The BKR6ES is usually found on Johnson Outboard marine engines and Polaris ATVs. This plug comes with a terminal nut. Spark plugs are one of the most common causes of electrical failure in a gas engine. Before potentially wasting money on other more expensive gas engine parts, consider replacing your old spark plug instead.