Experiments in boat speed...
 

"Shortwave Sportfishing" wrote in message
...
When I finally got a chance to run the Ranger's E-TEC yesterday, I was
a tad disappointed that I couldn't get the rpm's up over 4900. So
having the time to do some experimenting, I went back to my friendly
long time dealer and we decided to change the engine position one
notch with no noticeable effect.

So, we changed props to a 14 1/4, 21 three blade and there wasn't much
of an improvement - it handled a little better, but no increase in
speed.

Standing around the shop, scratching our collective heads, we noticed
a mechanical jack plate sitting in the corner that the owner had taken
off a Stratos on a E-TEC repower. The light bulb went off at the same
time - scramble around, install the jack plate, engine and took it
out. Got plenty of RPMs, but the speed wasn't quite what I wanted.

Switch the three blade to a four blade 21 pitch and voila!!!

Problem solved.

Pictures here.

http://www.swsports.org/images/P8033238.JPG

http://www.swsports.org/images/P8033240.JPG

http://www.swsports.org/images/P8033241.JPG


Glad you solved the problem. From an engineering standpoint, how did the
addition of a jackplate improve the top end? I am not familiar with
jackplates.