Counter rotating engine?

localboy · Posted: Tue Jul 12, 2016 6:17 pm Post subject: Counter rotating engine?

Can one mount a counter rotating engine as a single/primary outboard? Trying to answer for a buddy at work that blew up his two stroke and needs a re-power.

I could not think of a logical reason it would NOT work...

starcrafttom · Posted: Tue Jul 12, 2016 6:26 pm Post subject:

Torque one way or the other,does not seem to matter to me. Did he find a deal on one motor?

MikeR · Posted: Tue Jul 12, 2016 7:15 pm Post subject:

I once read that the reason the helm is typically located on the Starboard side of small boats is to counterbalance the torque caused by the prop rotation. But considering all the other variables such as passengers, gear, trim tabs, kicker motors, batteries, etc, I would see no reason it can't be done aside from possibly a limited prop selection, if counter-rotating props are sold in the higher pitches needed for twins (have no idea if that is true or not, as I've never had to shop for such props).

-Mike

tsturm · Posted: Tue Jul 12, 2016 7:27 pm Post subject: Re: Counter rotating engine?

journey on · Posted: Tue Jul 12, 2016 7:35 pm Post subject:

Journey On has used a counter-rotating Honda 150 for the last 10 years. Honda insisted that I take it and guaranteed the operation would be the same as a right hand rotation engine. So I took the motor and they financed the boat.

No problems with the motor operation. One has to search for the correct counter-rotating propeller but they're out there.

The answer is: either a RH or LH (counter-rotating) engine can be used as a single engine.

Boris

thataway · Posted: Tue Jul 12, 2016 10:42 pm Post subject:

No problem. Be sure to adjust the tab on the cavitation plate properly. Mike is correct that there can be minor trim issues. I have used counter rotating single. Also look for scratch & dent new motors.

localboy · Posted: Wed Jul 13, 2016 10:30 am Post subject:

Thanks all.

He is considering all options at this point. He is not concerned w/ the left torque, as his boat is loaded heavy to port. He was told there my by "an issue" with the hydraulic steering, but that makes no sense to me and I suspect it was a dealer who was less than forthcoming.

He is considering this option as a cost saving measure. The engine is a V-Tec. His boat is a 23' SeaSwirl Stiper with an older 2 stroke. The computer took a dump so...

Kushtaka · Posted: Wed Jul 13, 2016 4:02 pm Post subject:

All good advice. Green light! The big thing will be a trim tab ON THE Anti-Cavitation plate (not the big ones on your transom). Aside from adjusting, many CR outboards simply don't have them, and have a flat, round piece bolted in it's place. This makes your steering consistent in each direction and makes the boat all around happier and straighter running, especially at higher speeds.

The other thing that comes with the torque going left is when you are docking and come in to use revers, your stern won't drift left with the helm straight, it will now drift RIGHT!

Just expect it. Maybe it will help!