Re: RPM range @WOT
The tach may not have the proper setting for that motor. I say that because the 1993 OMC manual indicates that the powerpacks have a built in rpm limiter of either 5700/5800 rpm or 6200rpm depending on model. <br /><br />When I was setting up my 1993 40hp, I too had a 13 pitch prop that would let the motor over-rev at wot and hit the rpm limiter. It feels like the motor is loosing power or like the prop is not actually in the water. <br /><br />You didn't indicate what size/type boat its pushing, but with my boat/motor I ended up with a 15 pitch cupped Hustler aluminum prop turning 5000 rpm WOT. <br /><br />Depending on which model 40hp you have, the tach pole setting will be different. If you have the 12 amp regulated system (look for the rectangular finned aluminum regulator near the powerpack with the fins running vertical) set the tach to the 6 setting. If you have the 4amp non-regulated system, (no regulator) set the tach to 5. <br /><br />Edit: One important bit of info: Almost all tach manufacturers list the pole setting incorrectly as 5 for all 2 cylinder Johnson/Evinrude 40-50 hp models starting with '93. I spent a lot of time verifying the setting is actually 6 for 12 amp models. All 93 40 - 50 hp have a normal wot suggested rpm range of 4500 - 5500.<br /><br />Good luck.