spark issues on 89 120vro

[pappy.silver]

i have an 89 evenrude 120 vro and i'm having intermitten sparkissues.i have checked kill switch and unplugged it had spark and then didn't ni pullled off the power pack and checked wires .i'd like to know how to test it it has 5 wires goin in to it and then the black n yellow wire to the kill switch and the ground wire . i haven;t seen anywhere how to test to see if it is theissue ant help would be appreciated.