1935 sprark plug needed, opposed cylinder 21HP Help with this pls

[kodibass]

I have managed to get spark to the plugs but near as I can figure the autolite 386 that came with the motor seem to fire a weak looking spark, but when I test the spark with a checker it jumps a nice 7/16 to 1/2 inc gap. this is a 1935 evinrude 21 HP opposed cylinder motor 6011. I found a cpl references that seem to point to a champion R7 as possibly being the correct plug? if so is this plug available ? If you owned this motor what would be your plug choice??? thanks

 

[HighTrim]

Re: 1935 sprark plug needed, opposed cylinder 21HP Help with this pls

I am thinking you need the Champion D16 as the current plug. Ill check my listings later. It is still available through NAPA>

 

[82rude]

Re: 1935 sprark plug needed, opposed cylinder 21HP Help with this pls

my manual for my 22.5 hp opposed twin evinrude states that the r-7 plug is the next grade colder plug with the proper plug for the 22.5 being champion 5-mj.without going out and looking I know I got the 5-mj or todays replacement by champion at the local car parts store easily.

 

[HighTrim]

Re: 1935 sprark plug needed, opposed cylinder 21HP Help with this pls

The 5MJ replacement is the D9J

 

[kodibass]

Re: 1935 sprark plug needed, opposed cylinder 21HP Help with this pls

Thanks' I'll try napa for champion 5mj/D9j