Mariner 105 No Spark

[Tightlines99]

Hello I have a 1996 Mariner 105 Jet 0G129872 that is only making spark on the right bank of 3 plugs. Hoping someone on here can help me solve it. Ive heard about swapping wires on the switch boxes to test them, but not sure which ones to change. Hoping to get it fixed and back on the water and go faster than 7MPH. Thanks!
Thanks!