Proper plug gap

[ccsmith51]

I have RHM40E plugs on my O-360. I have seen recommended gaps from .016 to .021. I have also read in another thread that someone had starting problems with 0.022 and after regapping to 0.016 the starting problem went away.

So, my question is, what gap should I use? I just had the condition inspection done, and the mechanic checked and adjusted the gap, but I don't know to what spec (I will find out).

I plan on purchasing a gap gauge and gap adjuster from Spruce so I can check gaps at 50 hour oil changes, so knowing what is the best gap setting is of great interest.

Thanks,

[Mel]

For std mags, I recommend setting the gap at .016".
they will get wider with wear. Much over .020 can result in hard starting.

[ccsmith51]

Thanks Mel!!