There are several plugs recommended: 2 Stroke 1963-1966, NGK B6S, gapped to .025 1967-1968, NGK B6HS, gapped to .030 1986-2000, NGK BP8H-N-10, gapped to .040 2001-2006, NGK BPZ8H-N-10, gapped to .040 4 Stroke 2000-2006, NGK DCPR6E, gapped to .035
Johnson 6hp spark plug gap
.035
For a 1970 OMC 6HP engine, the recommended spark plug is the Champion J6C or an equivalent plug
Per Champion spark plug applications chart, the gap for 6hp Tecumseh engine is .030
It is usually a Champion plug RJ19LM. The gap is .030 inches. This plug is usually used with B&S engines from 3hp - 6hp.
If you are using NGK plugs, the plug model is BP6HS and the gap is 0.035. I had to look it up also for my 6HP Suzuki outboard on my sailboat.
The correct plug gap for the 1971 model, 6hp Johnson outboard, is .030-.035 in. It requires a Champion J6J, or NGK B6S.
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It is 0.030" for an L-head engine.
You can get it here: http://www.selffixer.com/outboard.motors/mercury/1986plus.Mercury.6-8-9.9-15HP.2-Stroke.Service.Manual.htm
RJ8C Champion
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