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.
WARNING California Residents
: Proposition 65 Warning
Specifications

Name:
NGK BKR6E-S
Thread:
14 mm
Reach:
3/4″ (19 mm)
Heat:
6 (medium)