my 79 rinker built has the 2.5 gm engine, mercruiser outdrive, 120 horsepower. My ? is the engine has a tag on it on the valve cover that says she should turn 3900-4300 w.o.t. but instead she turns about 4500, she runs excellent<br />gets up and goes fine but i am a little worried that i could cause damage or is maybe the tach off a little? I just put a new michigan prop on her a 14.5x 19 pitch. She is a 19.6 ft bowrider.<br /><br />Please help me comfort my mind when out on her.<br /><br />thanks 