85hp Johnson Power Trim

[McGR]

I installed a CMC trim/tilt on my '76 85hp at the end of last season. I only ran it once breifly before winterizing. Unfortunately, while I now had the ability to trim the motor, my boat was porpoising and I subesequently didn't see much, if any, performance improvement. In fact it was a bit of a let down, after doing what I thought was a nice installation job. Anyway... I'm thinking the setback may have something to do with it. This unit sets back the motor probably about 6". I set the motor at approximately the same height as it was when it was directly mounted to the transom. Should I possibly raise it higher? Or shoud I just add a hydrofoil? My rig would do 39mph (GPS) maximum last year. This year, I'm determined to break the 40mph barrier. So, any advice is greatly appreciated.

 

[DJ]

Re: 85hp Johnson Power Trim

Forget the hydrofoil.<br /><br />Setback applications require some tweaking.<br /><br />By setting the engine back 6" you have effectively changed the center of gravity (CG) point of your rig. That means weight distribution.<br /><br />You are transom heavy, now.<br /><br />Move anything you can forward.<br /><br />Once you accomplish that, you can experiment with moving the engine up, at small increments.