1988 mercury 90hp no spark on 2 cylinders.

Did the water pump impeller and lower leg seals a week ago. Fired up the boat in the driveway to check everything was good and it was.
Take the boat to the lake a week later and the engine wouldn't start.
Brought the boat home and figured it was the plugs but that wasn't it. Checked the kill switch and it was fine. From there I checked for spark on the plugs. Had spark on the one plug I tested and put the other 2 in. Engine started but I could tell it was not running on all cylinders.
Tested each plug wire for spark and only spark on the top cylinder and nothing on 2 and 3.

What could be the problem.

I have a trip planned for September long weekend and I hope to get it fixed by the

Charge battery and inspect starter.

It starts up but only runs on one cylinder. From what I can gather from the repair manual it sounds like the trigger assembly needs to be replaced.
I don't have a DVA to do all the multimeter tests. I have to order one.