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Struggling with a spark test (1956 Johnson 10)

S

shinola

Contributing Member
I have been trying to get a spark to jump 5/16" to 3/8" gap with a tester I got from an automotive store. It's not working yet, and I've traced down all items I can think of. I may be doing something wrong.

So here is my procedure:
1. remove both spark plugs.
2. Gap tester to desired gap. I've tried all the way down to 1/4" but was hoping to jump a spark 3/8.
3. hook one lead to tester and ground to head bolt (I checked ground continuity with multimeter).
4. Pull rope starter and look for spark jump.

So far, not much luck. To troubleshoot, I've done the following:
1. Replaced plug wires. Continuity checks tell me I've made good connections to the coil and spring.
2. Replace points with new and gapped. I think I did this correctly. After not getting the OEM's to fit, a set from Sierra fit perfectly and gapped correctly.
3. Replaced condensors. Probably didn't need to, but I had new from the tune up kit.

Any ideas or pointers would be appreciated.
 
3/8" is difficult to achieve on those.-----Are coils located correctly ?-----Are coils new ?----Timed points with a meter or feeler gauges ?----Any spark at all ?
 
I believe the coils are located properly. I bought one of those fancy CDI rings. Fits perfect on the 3 surfaces on the magneto plate, then I snug the coils up to the ring and tighten. After removal of the ring, they appear to be right at the inside edge of the chamber on the mount locations.

I did not buy the coils new, but they are definitely not original. I believe there is a picture of them on another thread. They are the red plastic coverd coils. They look like new, but I don't have any info on how old they are or how many hours of use.

I gapped the points with a feeler gage with the cam follower on top of the cam thickest portion. Watched some Youtube videos and read some manuals. I think this is correct, but it's my first attempt.

I did get an occaisional spark at 1/4" on one cylinder. Never saw a spark on the other. Didn't write down which was which.

I should note that a member of the AOMCI (went to a meet on Saturday in Lake Shipp FL). mentioned to me that oild from feeler gages, or even oxidation on the points could prevent good electrical contact, but I checked with multimeter (wires removed) and got good connection. Still cleaned with sand paper and alcohol wipe to make sure.

Brian
 
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