Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Counter Rotating Lower Units

Posted by jsneed on 11/20/06 - 2:04 PM
#1

I just acquired a 1982, 25' Outrage with twin 1999 Johnson 150's. The engines are like new, but are not counter rotating. Is it possible to change them to counter rotating by changing a foot on one of them, and if so what is involved?

Edited by Tom W Clark on 11/22/06 - 10:03 PM

Posted by Tom W Clark on 11/22/06 - 10:11 PM
#2

Maybe. The trouble you may find is that if your motors are 20" shaft models, which I suspect they are, you will find that OMC did not make counter rotating outboards in that shaft length.

I had that same problem in my Revenge 25 which has a pair of 1989 Mercury 150s which were not counter rotating. My solution (which has not been entirely concluded) was to buy a counter rotating lower unit from a 25" shaft length model and having the drive shaft cut down to a 20" and then splined to fit into the powerhead.

Before I did this I asked around and received a variety of opinions about 50/50 as to wether I could do this or not. I did it anyway and found a guy in Pennsylvania who did the cut and spline for about $150.

On the Mercury outboards, the shift cable function has to be reversed for the counter rotating unit, i.e., push to pull and vice versa.

I do not know if any of this is applicable to the OMC motors.

Edited by Tom W Clark on 11/24/06 - 4:48 PM

Posted by Jeff on 12/02/06 - 7:57 AM
#3

In all honesty I cannot imagine going through all of that trouble. We run twin non-counter rotating Merc 150's on the 22 Guardian. After a summer of use I have not encountered a situation where I felt this set up was a major deficiency. I would suggest if you just bought the boat to run it for a while in it’s current set and see what you think. I bet you will find that it is not to bad.


Also Tom,
What is the name of the guy who did your work?

Posted by Tom W Clark on 12/02/06 - 9:41 AM
#4

Jeff,

I'll have to look that up and get back to you but he did what he said he was going to do and he did it well. It was a recommendation from the Scream and Fly site where he does a lot of work.

Posted by jsneed on 12/04/06 - 7:09 AM
#5

I have 25 inch shafts not 20's, but they seem to be fine. The problem I have noticed is the boat listing under high throttle due to the torque from the props. Also, I have noticed that it does not throttle steer (one engine in forward one in reverse) as well as boats I have driven with counter rotating props. If I cannot change it, it is not a big deal, but if it is not a complicated fix I want to look into it.

Thanks for the posts, Jeff Sneed

Posted by Tom W Clark on 12/04/06 - 8:18 PM
#6

Jeff Sneed,

What sort of brackets are your motors mounted on?

Posted by Tom W Clark on 12/04/06 - 9:45 PM
#7

Jeff,

The guy who cut and splined my lower unit's shaft was in Connecticut. His name is Russ and his business is D.J. Marine, 860-345-8721

It was the oddest thing. I bought the used lower unit from a guy on Scream & Fly and he recommended Russ. I just called Russ on the phone and told him what I was up to. He said he did it all the time for the hot rodders and that he would wait for the lower unit to arrive at his shop and then assess whether it was in good condition. When he received it from the seller, he called me up and said it looked fine and told me he could do the job.

He did an excellent job boxing it up in an old bicycle box and shipped to me for about $60 or $70 coast-to-coast. I believe I just mailed him a personal check. It was no big deal at all.

Posted by jsneed on 12/05/06 - 8:25 AM
#8

They are not on brackets at all. Why?
Jeff

Posted by Tom W Clark on 12/05/06 - 12:07 PM
#9

Jeff Sneed,

Your 1982 Outrage 25 is designed for 20" shaft length twins, not 25". If you really to do have twin 25" shaft motors on your Outrage, you are dragging around and extra 5 inches of motor through the water! You could substantially improve the performance of your boat by installing jack plates to set the motors to the correct level.