Oceanpro 225 missing under load

I have 1997 Oceanpro E225TXEUD that was running fine last year. This year it was missing heavily when running full or close to full throttle. My mechanic said the flywheel magnets were misaligned. After getting that fixed it ran nicely at idle and is not missing but would not get full power. Mechanic said two cylinders were not firing - he replaced the power pack - now its running even worse - heavy cylinder miss at half throttle - runs ok at low speed. I replaced two plug wires that looked corroded - no change. Any ideas? Mechanic seems to be stumped. Could it be bad ignition coil? Could it have been the two spark plug wires and the "new/refurbished" power pack is bad?

Are you running on last years gas? Post compression numbers.do it got spark on all cylinders?has your mechanic done any testing?

We had about 25 gallons from last year, we've added 50 fresh. Its getting spark on all 6 cylinders at Idle. Hard to check when running in the water(runs great at idle/slow speed - not when under power. Haven't done compression test but assume my mechanic checked that - will ask.

My opinion,adding fresh gas to old gas just makes more bad gas!
Whos working on this,you or your mechanic?
Plugs filters,has any maintenance been done,this year?

Hear you about the gas but we've been doing that for years and never had an issue. The Mechanic has been doing (most of) the work, but after several failed attempts, I'm wondering if he is at the end of his road. Knowing a bit about engines, I'm sort of second guessing him. I suspect the issue was both the plug wires and the flywheel magnets, and replacing the power pack has just introduced a new issue - but I'm no expert - thus my fishing for opinions on this forum. As far as maintenance goes -the plugs were replaced last year and it was running great - this year both the inline and main fuel filters were replaced.


BTW - we have an issue were the thermostat sometimes drips water on to the starboard side plugs. We have a "shield" in place to remedy that but that (I believe) is the cause for the 2 bad plug wires.