Reply To: 1955 big twin – bottom plug fouling

[bob-d]

Red Boat, a super simple test for spark in the entire circuit is just take the plug out of the motor, insert back into connector, and ground on the powerhead. I use small flat  round magnet from Home Depot to hold the plug against the powerhead. Gives a good connection,  and is a super easy method. Make sure the lower unit is in a barrel / lake crank the motor, and check for spark.
You can change plugs very easily with this  testing configuration to see if they are the problem. I hate to say I have never had good luck with Atom modules, but as they say …. individual result may vary. Don’t be afraid to swap coils, or go back to good old points and condensers. Check your boot connector on the top of the plug as well. I had a brand new coil from CDI once that was a dud. Electronics in todays boating world can be dicey. Not the same quality as before. Good luck, you will figure it out.
Bob D