71 SKITWIN NO FIRE BOTTOM CYL

[RDSJR]

I have a 71 skitwin with a no fire on the bottom cyl. I'm sure I checked both and were good to begin with. Since then I had the starter rebuild and carb. Lost fire somehow on the bottom cyl. Could it be the wires on the cutoff switch or ignition switch. A few wires fell off the switch and since then have had trouble making sense of what previous owner done ..

For example I can get it to start but not shut off using the key switch. It was a hack job when I got it so at the point loosing patience. Points etc are all new...

What wires go to the vacuum cutoff switch...

 

[F_R]

No Title

Everybody is quick to blame the cut-out switch, but it is highly unlikely to be the problem.

Wired wrong? Well now that is possible.

Been messing with the ignition switch? That can cause destruction of a coil if wired wrong.

This is NOT the correct diagram for your motor, but the part you are interested in should be the same.

 

[RDSJR]

Thanks I will give it a shot. Someone uses a different wiring harness to the switch, so I have to remove a ton of black tape to see which wires are at the switch.

 

[RDSJR]

I have a busted coil...looks like the housing hot onto it and busted the coating on it...will replace and update

 

[racerone]

Age cracks those coils.-----Every one of those vintage magnetos has had the coils replaced or needs a set of new coils.

 

[F_R]

Incorrect ignition switch wiring will explode even a new coil. But yes, the old ones are expected to be cracked from age.

EDIT: Using one of the black kill wires to ground some accessory will also explode the coil

 

[RDSJR]

Everybody is quick to blame the cut-out switch, but it is highly unlikely to be the problem.

Wired wrong? Well now that is possible.

Been messing with the ignition switch? That can cause destruction of a coil if wired wrong.

This is NOT the correct diagram for your motor, but the part you are interested in should be the same.

LDiagram worked great, thanks. Found an OEM ignition coil at a local shop. Getting fire on both cylinders now. Just a PEA for anyone else...these are simple motors just take your time running the checks, air file and fire.