1974-50hp wont fire and run

[Buckshot]

The motor spins and gets fuel but does not fire and run. I took out the plugs and put them back in and it ran for a few seconds. Could it be the power pack and if so is there a way to test it? The plugs were not fouled.

Any help would be appreciated.

[GearheadZ71]

Coil on plug ignition spark checker. They run about 10 bucks. The brightness of the flash, or lack there of, will tell you the overall health of the system. Just ground it out, insert into the boot, then turn it over.