Cub 124
 

OK, odd issue I'm having today. When I go to start it, it will just turn over but if I pull plug wire off and jump spark it, will run but if I hook it up it kills it.

Examine spark wire and spark plug and replace if necessary. My guess is something's grounding the spark.

Wire and plugs are fine just don't understand how it will work if I jump spark on plug or coil it will start

Check points, when it is running does it throttle up?

If iam able to hold wire above coil to keep it running I can throttle up but now I think I lost spark altogether now

I'm going to start with changing out coil

Ignition coil testing info: https://www.onlycubcadets.net/forum/...highlight=coil

Like Lew says, I would inspect the points AND condenser, too!

Points
 

I think points are working opening and closing with spark

Ok so pulled plug got good spark but still will not start

OP has sent me a PM indicating he has replaced everything and has good spark but no start. So I'm bringing this back to forum for all to see and share their thoughts. Assuming fuel and compression is good, I think maybe timing is suspected:

Using timing light:
https://www.onlycubcadets.net/forum/showthread.php?t=14

Using a multimeter:
https://www.onlycubcadets.net/forum/...ead.php?t=4405

So it wont pop off with starting fluid?

Spark but not even an attempt to cough to life would seem to suggest timing or something catastrophically wrong with the valvetrain. I would lean much towards the former, especially if "everything" has been replaced.

Low compression will cause that symptom also.

:IH Trusted Hand:

Remove the plug and place your finger over the hole and crank.
If the valves are operating properly, you should feel compression at this point.
I would not use starting fluid as it will wash down the cylinder walls.
A small shot of light oil should give enough lube to increase compression in a dry cylinder.
This, and I would opt for a small shot of carb cleaner into the carb.
If you have compression, spark and fuel, and the points are adjusted and timing is on, it will run.

Here ya go. To have a successful ignition, the Holy Triangle must be met.