Re: 4 Stroke Repower
Old Curmudgeon,<br />I re powered from a Merc 115 2-stroke to the Johnson/Suzuki 4-stroke so I had to change about everything, no help in that department. Otherwise, the 140 is a sweet motor. All I've done is change the oil. These engines are somewhat hard to prop. You've probably noticed the low gear ration of 2.38:1. My rig definitely performs best with the 14" diameter props. I tried several of the 13.25" props from various different aftermarket sources with little luck over a two month period. Its sort of a catch 22. The smaller 13.25" props have a tendency to blow out coming out of the hole because of the engine's low gear ratio. Increasing the pitch will help the blow out problem but then you're over propped for top end and can't get into the upper end of the recommended WOT RPM range. Get the WOT RPM right then you don't have enough prop for the hole shot. See what I mean? Its all about the gearing. Any Mercury 15 spline prop for intermediate gear case will fit the shaft but the blades are too small in diameter. I also tried a Trophy 13-3/4" X 23 4-blade but it still didn't perform near the Stiletto on my setup. Presently only OEM and Stiletto (
http://www.stilettopropeller.com/ make props specifically for these engines (14"), to my knowledge. I ended up with a Stiletto SS on my rig, works great.
