Flathead/Magneto/Gap?

Getting ready to drop a Vertex Mag into '50 Merc. I read somewhere once that the sparkplug gap should be .022". Seems a little skinny. Anybody done this? What gap did you use?

 

Yessir......018" - .022".

 

For low-speed operations you need the smaller gap - in a perfect world, you could vary the gap & widen it once you got it started.

Had an old XLCH chopper years ago & put some plugs in with a normal gap of .035 - I could barely start the thing - I kicked forever & ever. One day, one of my buddies told me about the gap - 2-kick start after that.