[burkepf]

Bike is a 1970 CL350 - I am not getting spark on the left side at the plug boot. I have pulled the spark plug boot and attempted to ground to the engine and confirmed no spark on left. Did same for right and confirmed right was making spark. I removed the points cover and confirmed that spark was happening for the right side but not for the left.

To test to see if it was the condenser I switched the pig tail leads for the condenser to the opposite coils. I was able to confirm both by grounding the right spark boot to the engine and seeing the spark at the right side point but the left still was not sparking at the point or the boot. I switched both pig tails back to their original coils.

Then to confirm that it wasn't the wires that connect to the points I swapped both to the opposite coil as I did for the condenser and was able to get spark on the left coil and confirmed it at both the left point and the left spark plug boot grounded to the engine but now I couldn't get spark at the right side point or boot.

Tested resistance on left coil. Yellow lead to black white lead is 5 ohms. Yellow lead to spark boot is about 19k

Tested resistance on right coil. Yellow lead to black white lead is 5 ohms. Yellow lead to spark boot is 16k.

Battery voltage is 12.2

When everything is set up correctly and I don't get spark on the left side the left coil warms up pretty quickly to the touch.

I am a novice and have little experience. I am mechanically inclined but anything electrical is intimidating to me. I understand it in theory, but can't put it to practice. I've been chasing this gremlin for about a month. Want to make sure the coil(s) is(are) shot and that they are the issue before I drop money on a new set, replace them and still have the same issue.

 

[66Sprint]

Phone while at bike with multimeter , a shop-rag, and a book of paper matches.....
I suspect the left points are not breaking and/or the point wire to them is grounded......
5 minutes of testing will tell.... 540-525-5199....Steve

 

[a_king]

and a book of paper matches.....

i am *very* interested by this...

 

[66Sprint]

Matches are to wedge between points to keep them "open" so continuity and voltages can be checked without risking "cooking" the coils.....

Simple and effective.......

 

[83XLX]

I had the same problem and it was worn out points that caused it. The point arm was moving back and forth on the pivot instead of opening and closing. Your battery voltage is a bit low, too.

 

[burkepf]

Hey Steve I just tried to reach out.

Thanks,

Pat

 

[burkepf]

Thanks - It's Back Up and Running!!

Steve - Thanks again for your help.

Was able to pull an insulator for the left point connector lead from a set of points a friend had sitting around.

---

As for what the issue was. Using the match book as directed to keep the points open and then with a multimeter I tested continuity. Turns out the left points lead was grounding on the points plate where the lead connected to the bottom of the points spring which isn't supposed to happen. Steve graciously offered to send me some old points parts in the mail but fortunately a buddy around the corner had an extra set of points that I could pull the insulator from. Picture below of where the insulator is on the left point (red arrow). Mine was nonexistent - the previous owner tried to fashion their own insulator from resin/plastic and it must have worn out over time. Was able to fix it up and take a my first ride in about 2 months - it was awesome.



So thanks to Steve I was able to save myself the ire of spending money on new coils that wouldn't have fixed anything. Now I know I can replace the coils (which are still original) along with plug caps and spark plug wires (most likely from mikesxs universal coils, non-resister plug caps, spark plug wires) and they should work. Thinking about replacing the breaker lead as well - does any one know of a good place to get one or will the one from mikesxs work. I also plan to replace the points and condenser as well, this set from common-motor looks like it will do the trick. The common-motor team also has a pretty good video (below) on setting the timing when you replace the points. Let me know if there are any other options for replacements that will work or you have had good luck with.

Pat

 

[aram]

I am having this same issue but with the right side. Ive done all the same tests and I'm thinking I am having a points issue, but I really don't know how to fix it. Any help?