Thanks Silvertip, from my experience, any outboard that has hardly been used, and has been grossly neglected is likely to need a full overhaul, plugs, lower unit oil, impeller and or water pump body, to me that would just be routine to catch up for seven years neglect. I did not give you the full info which made me think the gauardian system had triggered, twice underway at 4000 the alarm went off and the revs dived to about 2000. I gave it alittle time then slowly went back up to 4000, fortunately the trip was only fifteen minutes long before being hauled. I understand your concern about 6000 revs, but this was only once for a brief second, to see if it was a gearbox problem or not. I have since discovered that the vent was not cracked open on the portable fuel tank, so that may have starved the engine of fuel, but then it wouldn't have carried on after slowing down? As you see i have much to learn, and the Mercury manual should be here soon. Talking of checking the plugs, there is so much stuff attached to this engine, I can't even get a finger in to pull off the plug leads, is there a secret to this, or a special tool?
Thanks in advance ...