1989 Mercury 100 4cyl - Ignition Spark Issue (S/N: OB346208)

[rcwannab]

Relatively newbie here that just purchased 1989 Mercury 100 for a learning project.
Mounted and rigged on project boat, but at WOT only getting 2,500rpm.
New gas, new fuel lines, primer bulb, rebuilt carbs, performed link/sync.
Starts with bump of the key, idles great, but no WOT.
Checked spark; both top and bottom cylinders not sparking across 7/16 gap.
I shuffled coils and the no spark issue remained unchanged; still no spark on top and bottom cylinders.
I shuffled the wire from switch box to coil and the no spark issue followed the CDI wire change to another coil pack.
Need some reassurance and assistance on next steps to isolate or eliminate switch box, stator, trigger as this is uncharted territory for me. Thank you in advance.

 

[Faztbullet]

I shuffled the wire from switch box to coil and the no spark issue followed the CDI wire change to another coil pack.

Explain this a lil better...did you move the green coil wires from ones not firing to a firing one and then that one would not? If so change switchbox. Its not trigger as pairing is off and it has a stator adapter

 

[rcwannab]

Explain this a lil better...did you move the green coil wires from ones not firing to a firing one and then that one would not? If so change switchbox. Its not trigger as pairing is off and it has a stator adapter

Yes. I moved the solid green from top coil (not firing) to second coil and moved the green/white from second coil up to top coil. This resulted in the top coil now served by the grn/wht to properly spark and the no spark condition to move down to second coil. Did same swap with lower two coils green wire sets with same result.

 

[Texasmark]

To ensure that your problem is only electrical, squeeze the primer bulb when trying for WOT RPMs. If you get them new fuel pump kit and probably should do a new fuel filter and cut the old one to see if black or tan specks/chips are in it and if so change your fuel lines from the tank all the way to the carbs.

 

[rcwannab]

Thank you Faztbullet. Got a new switchbox and resolved all issues. Outboard runs better than ever. Thank you all for the collective wisdom this forum offers.