What should spark tester gap be set to for coil wire?

[brider]

I have a '67 Johnson 60 hp Super Sea Horse with no spark at the plugs, although power is getting to the coil and points. I bought a spark tester that you insert into the coil wire (can also use it on a plug wire) and ground to the engine, and I found SOMEWHERE on this site an Evinrude manual that specified this spark gap, but can't find it now (didn't write it down, duh!).

Engine spins over fine with the starter key, just no spark. Checked plug gaps and point gaps, all good.

Can anyone help a brother out?

 

[GA_Boater]

It should be about the same spark gag as for testing at the end of a plug wire. But really at the coil any spark is good when testing for spark.

 

[schematic]

3/8 - 7/16" gap will prove the existence of spark and also stress the insulation of the coil and wires. A small gap won't always show up any weaknesses.

 

[brider]

Thanks, I'll set it at 7/16" and go from there.