Weak or no spark 1962 Model 70 original 47420

[Martin Davidson]

Hi all just started to inspect my new project and somebody tried to get it running. New plug, points and fresh oil but I think they gave up because theirs no spark. I need to test the mag and condenser.
Thanks for any help

 

[kmcconaughey]

Here's the schematic for an original with electric start:

 

[Martin Davidson]

Thanks for the quick help but my cub is a pull start with a mag. Any help about testing would be great
Thanks

 

[mfrade]

Thanks for the quick help but my cub is a pull start with a mag. Any help about testing would be great
Thanks

Pictures Please!

 

[kmcconaughey]

Pull start:

 

[gpapa]

Can you ohm test the Magneto? Are all the ground connections shiny and tight? You can also check the resistance on the wiring and spark plug. I’ve gotten some defective new parts, new=never ever worked; so check them too. Good luck

 

[Martin Davidson]

Yes I did test the mag and all the grounds all checked fine except one side of the mag is dead and the epoxy coating is all broken and the condenser is questionable.
Thanks

 

[bjames]

I replaced my mag coil several years ago with this. You need to solder the plug wire to the loop and I think extend one of the wires.

https://www.oldmercs.com/product_p/399-125.htm

 

[Martin Davidson]

Great so theirs an exposed wire on the mag to solder to did you find a condenser?
Thanks for your help

 

[bjames]

Great so theirs an exposed wire on the mag to solder to did you find a condenser?
Thanks for your help

There is a metal loop to solder to. I think I used my old condenser but here is a replacement. You may need to extend wire. It's been years ago and I don't remember.

https://www.oldmercs.com/product_p/399-123.htm

 

[Gary Hall]

A bad (open) condenser will cause a weak spark.
If your meter has a capacitor test function ones I've checked are about 0.22ufd to 0.47ufd.
I've had bad new ones.