I have a 2007 Lund 1700 Explorer Tiller model (1035 # dry). I am running a BRP Rogue 13.25 x 15 4 blade prop. My E-Tec is rigged on the third hole down. With this set up I'm getting 5400 RPM and 36.4 MPH GPS. I have tried a BRP 13.25 x 17 SST prop (3 blade). The max RPM I could get out of that prop was 5000. I then tried a PowerTech OST 13.25 x 16. This put me at 5250 RPM and I could get 39.5 GPS when trimmed out. The big problem with that set up was at WOT the boat control was bad. One of the moderators / tech guys on E-Tec Owners Message Board recommends the 4 blade BRP Rogue for the E-Tec I-3 motors (75 & 90). This one seems to work the best. Last Fall a friend of mine let me try a Solas 13.25 x 15 4 blade and that prop also preformed very well. I got 5300 RPM and 38.4 MPH GPS trimmed out. [COLOR=black][FONT=Verdana]I probably could use a BRP 13.0 x 17 Rogue 4 blade, and that would put me at 5200 RPM which is the sweet spot for the E-Tec I-3 motors. [/FONT][/COLOR]
[COLOR=black][FONT=Verdana]Since you are only seeing 4800 RPM with a 15 pitch prop, I would checkthe mounting height.[/FONT][/COLOR]
I was talking with one of the other guys and he said u had a 75etec. I just bought one and have it on 175 magnum. I was wondering what prop you were using and what kind if speed and rpm you were getting. I have a 15p on it and I'm only getting 4800 rpm's.