Re: 140 4 STROKE
twofing,<br />I doubt seriously if the 140 4-stroke would out perform your 135 in the power/speed department. I replaced a Merc 115 2-stroke on my Tracker Avalanche (1500 # hull) with the Johnson/Suzuki 4-stroke. The 115 would push the boat around 46 mph, I now go around 50-51 mph tops. I have over 200 hours on the 4-stroke, no problems whatsoever. It is quiet, smooth and quick starting. I think it is a great engine but my purchase was based on economics. In my area the Johnson/Suzuki 4-stroke was around $2,500 less at the time. As previously stated, it is a beefed up, bored out, tricked out 115. It doesn't have the displacement of the Yamaha or Honda 150. As Suzuki advertises in promoting their larger engines; "there's no replacement for displacement". Although the "JohnSu" has a redline of 6200 RPM, the gear reduction is 2.38:1. I'm running a 14 X 24 SS prop.@ 6100 RPM's/50 MPH,GPS.<br /><br />Go to the engine manufacturers site and check out their performance bulletins. They have their engines tested on various different types of boats. Maybe you can find one similar to yours.