Hi guys, I'm new to this site, and have a lot of questions. I will try to make this as short as I can. Problem: 1989 Evinrude XP150 model# E150STLCEM with ignition problem.Two years ago motor quit -not firing. Local mechanis said bad power pack; replaced-- back on water--six fishing trips--down again. Local mechanic sent me to another mechanic who replaced what I call the trigger (part under flywheel with six firing points).Back on water for several trips. Boat sat for 3 months during winter, No batteries hooked up. Last spring developed firing problem again, firing on 4 cylinders. 2 not firing #3and #5 cylinders. I tested spark by removing all plugs from engine and made sure they were grounded to block. Out of curiosity I put the old power pack-(one with no fire at all)- back on motor, and now have fire on all cylinders except #6.Replaced pack back to newest one--still not firing on #3 and #5. Moved primary wire going to #1 coil down to the #3; and #3 primary wire up to #1. Now getting fire on #3 but not on #1.I figure coil for #3 must be good--would you agree? If the coils seem to be OK do you think I will have to replace power pack again? Is there something that I am doing wrong that is causing the packs to go out or is this common? Should I unhook the battery to the engine or is it OK to leave it hooked up? Any info on ways to test ignition would be greatly appreciated.