I've finally figured out my intermittent power loss problem. Since last fall, on rare occasions the ski would totally loose power, then would run fine. This spring it started happening more frequently. The last time out it would happen every few minutes, but then run great. I checked plugs several times right after it bogged down, and they were soaked - full rich. About a week later the ski wouldn't start anymore. I figured electrical problem. Started by cleaning the main electrical plugs. Still wouldn't start. As soon as I disconnected the EFI unit and bypassed it the ski started right up and runs great. The lights on the EFI unit are still functioning properly, but it's dumping full rich fuel constantly. This is my 2nd controller failure. The 1st time I lean seized when it failed and reverted to stock mapping. The lights stop functioning that time. This time it's full rich. It's just suprising that it started off as an intermittent problem that really had me stumped. A couple of times when it bogged down, it picked up a stepping motor malfunction. That's what had me looking at other things. I'm guessing the steeping motor was trying to compensate for rich fuel by increasing rpm at lidle speeds. An intermittent problem with the controller really never crossed my mind. Not until it totally failed did I bother to check it. BTW, this controller had over 200 houirs on it.
I learned that from now on whenever there is any kind of fuel delivery problem, check you controller for proper operation.