counter rotation location

I've been working on my two 1991 150's lower units..thanks to those who've helped me. But i've managed to switch locations so many times, i can't remember which one is the counter rotating one. How can I tell which one is which? I've always seen the counter rotating engines mounted on the left. What is the reasoning behind this? Thanks in advance.

Re: counter rotation location

Look real close at the end of the propshaft. There will be a "C" stamped in the backwards one. Or just put the gearcase in gear and turn the driveshaft clockwise. The standard one will turn the propshaft clockwise.<br /><br />Where the c/r is palced depends on what your looking for, set up and hull configuration.<br /><br />On cats or tunnels we like to put the left (c/r) on the right (starboard) and the right (standard rotation) on the left (port). On V bottoms with no set back or step the right on right and left on left. With a step or set back we go left on right and right on left.<br /><br />A lot also depends on the props. Obviously you've tried it both ways. Which ever you like is OK. There is no wrong way.<br /><br />Experiment with your toe-in also. Sometimes it makes a big difference.

Re: counter rotation location

Just curious - is the counter-rotation achieved through the gears, or does the engine actually run in the opposite direction.

Re: counter rotation location

Thru the years it has been done both ways but the most popular nowdays is strictly with the gears.

Re: counter rotation location

as luck would have it, there's pitting on the end. I've sanded with 220 wet, but to no avail. I can't tell if there's letter or not. so i pulled up on the shifter and rotated the propshaft, the driveshaft followed suit - in both directions. I did the same to the other lower unit and got the same result. Any more suggestions...aside from remembering to mark them next time.

Re: counter rotation location

If you pull up on the shifter and rotate the driveshaft clockwise each unit will rotate the propshaft in opposite directions.<br /><br />If they both react the same, you have two standard rotation gearcases. Are the props different?

Re: counter rotation location

thank you very much. Yep the counter rotator propshaft turns ccl when the driveshaft is rotated clockwise. Exactly opposite the "regular" one. And yes, I do, have two different props, one right-handed and one left-handed. Whew! it's getting late so i'd better quit for now. Thanks again for your help.

Re: counter rotation location

Cool! Let us know how you prefer the set up. And what kind of boat and its performance.<br /><br />Good luck!