I have gone through the forums and found some interesting information but not sure if my particular problem has been addressed. Just recently acquired a 1994 Donzi 152 Medallion with the sport jet 90 Mercury. Firt 6 or so trips out on the water proved enjoyable, had top speed in low 30's. Recently power has dropped off and top speed is not there. My WOT RPM is only about 4725. I seem to be getting good spark at each spark plug. Engine seem to have rough idle when timing set to 30 btdc. Once the engine warms up, I can advace the timing to 34 and the engine seems to run a lot smoother and more power but once engine cools, has no power at WOT. I have replaced the spark plugs and at one time remove the plugs and the #3 spark plug came out clean where the other two were black but center elctrode had nice gray burn to them. I suspected water intrusion in the cylinder but swapped plugs around and did not get another clean plug out of #3. I do not have a problem with starting, starts pretty easily. As I get to WOT, there is a little hessitation and power does not seem to be there, does not even want to plain out and that is even with trim tabs installed. Again this is when the timing is set at 30. I believe at one point that I got a hold of some bad gas and I have since drained and refilled with good gas. Does anyone have any suggestions for me. <br /><br />And before someone ask the question, my stator is black and not red.
