1988 88HP Johnson 2 of 4 cylinders not firing

[KennyG]

Running at WOT all at once loss of power. It appears 2 plugs firing 2 not. Changed CDI block and both coils and checked stader. No change. Help?

[Joe Reeves]

The terminology of "appears" doesn't really tell us anything. Which two cylinders are not firing? Standing in back of the engine, facing the spark plugs, the cylinders are numbered as follows:

2....1
4....3

[KennyG]

1988 88hp

Cylinders 2&4 are not firing, 1&3 are