KZ900 2 & 4 dont seem to be firing

Kz900 1976 starts with choke on, wont idle and seems cylineder 2 & 4 not firing? Is this a valve issue or carb issue. Running dyna S ingnition?

You need three things to fire...compression, spark and fuel.

Have you done a compression test? If compression is OK then it's likely not a valve issue.

Are your coils properly hooked up? Left one goes to 1 and 4. Right one goes to 2 and 3.

Have you checked your plugs to see if you have spark?

If you have compression and spark then your problem is likely carburetor.

How long has it been sitting?

Thanks I will check all of these