I have a 1985 30' chris craft with twin 350s. when I bought boat I did a compression test, 127-140psi on all cyls. Drove boat to marina in Key Largo. Both were running fine. Three weeks later starboard engine fires right up. Port side turns over but wont run. Check the thunderbolt IV ignition with troubleshooting procedure I found online. It shows to be good. I swapped carbs to see if that was it nope. With spark tester I show spark at plug. When looking at spark at end of spark plug it is orange not white or blue. Also other things ive done. New cap, rotor, wires, and plugs gaped at .040. And they share fuel from same tank.
Any ideas?
Any ideas?