Have 04' Optis and having a problem with one of them going into guardian saying "low driver power". Does anyone know what might be causing this? Mercury says it's a bad coil yet, I've checked all of them on this motor and they are all fine. Been inside and out on the wiring harness and it seems to fine everywhere as well.

Since you have twins, and merc says that its a coil, why not swap them all from one motor to the other and see if the problem follows. I believe Opti's use the same CDM(coil) as the older 3 liters, and I have had a few go bad on me, so its not out of the question to have a bad one. Where are you located, I have the CDM test harness to test them properly if your local to South FL.

Unfortunately not local to south FL.....Virginia Beach, VA but do appreciate the reply. I'm waiting on the other power head to come back from Powerhouse Performance Machine in Ormond Beach, FL now. Should have been in last week so hopefully it will come this week. Boat went underwater in MD where I got it from about 2 months ago and have been trying to get it right and back in running order. Couldn't pass up the deal at the time but this is becoming quite the headache. I will certainly try that when it arrives.