When you try to jump a spark to the terminal of an installed plug, the current has to jump two gaps, the one to the terminal and the one between the center post and the shell. If you get a nice blue spark to ground or in the plug when it is out and grounded, you have good spark.
A really hot mag would jump a blue spark to the terminal with the plug installed, but if it doesn't look so hot that way, it still is probably good enough.
recheck your point gap, maybe even make it a little tighter, like 12 thou.
Change the spark plugs if you have some spares and then try. I bought a spark tester that clamps on to the engine with spring clip. Works good for testing the spark and you don't need a helper to use it.
Thank you Jim Davis,drujinin, rmyram, and fordhook for your help. I have copper wire but I did not know about the spark having to jump two gaps, also that faster rpm gives more spark. The tester sounds like a good idea but drujinin cracked me up with his idea of his least favorite friend holding the plug wire. I will check the points gap again and close them a little to see if it helps. one last thing what is the best plug to use for this pony?
1canoeman1
Not sure if they are the same but i am running NGK ab6 plugs on my 9u ponies, they are the large thread plugs, i ahve seen some ponies with the smaller thread plugs. I'm sure someone with a d2 or d4 will chime in with what works for them, pretty sure your local parts supplier can supply a plug as long as it is the ones that cause interference with radio stations it should be good, Pretty sure they are caled non resistor plugs, I purchased mine at the local NAPA store, they had them in stock.
Thank you all for the plug info.Different plugs will be the next thing I try. I have never owned a Cat before so this site has been a huge help.
1canoeman1
Hi Team,
have found some good info from an old Service Reporter April 1960.
Hope it helps someone out.
Note my prefered plug gap of around 0.022" for use with our old depleted insulation quality magneto coils.
Get these while they are up. They may be suitable for the Service Library.
Cheers,
Eddie B.
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