1997 Mariner 20EH ignition issues

[Bullie]

Working on a motor for a friend. His 20 hp Mariner had no fire. He said the switchbox had been replaced last year. I cleaned every connection I could find, disconnected the kill switch, and could never get any fire so I ordered a new switchbox and installed it. Now I have spark jumping 7/16 on one cylinder. To test and see if it was a coil issue I swapped the leads to opposite coils and the spark moved to the other cylinder. I have reached the end of my knowledge. What do I need to do?

Compression is 120/118

 

[CharlieB]

What triggers the switchbox? I would need model and serial to look up the parts view to refresh my memory.

If this is an old point triggered system double check the plastic insulators on the points wires. Those things had a habit of cracking and an arc can occur through there unseen, killing spark.

 

[Bullie]

06512248 1997 20EH

I wouldn't think it would have points but, what do I know...

 

[Bullie]

Anyone? The two wires leading to the switchbox from under the flywheel, having never worked with one of these motors before I assume they are the leads for the trigger? Would I be on the wrong track to test that both leads are conducting a charge as only one cylinder is firing or am I misunderstanding how the spark alternates to the cylinders?

 

[flyingscott]

If the spark moved to the other cylinder with the coil swap you have a bad coil. Did you swap the 2 green wires or did you swap the spark plug wires. The only thing under the flywheel is a pick up very seldom do they go bad. You do not have points. If you have spark the pick up is good try a new coil.

 

[Bullie]

I swapped the green wires from the switchbox to the coils. Both coils fired with the same lead from the switchbox. I assumed that eliminated the issue being a bad coil.

 

[Bullie]

I must have finally gotten a good connection somewhere. Running fine now. Thanks again.