counter rotation on twin outboards

[Hank49]

I may be setting up a 29 foot boat with twin ETEC 150s. How do you set up counter rotation? Right rotation on starboard? Or right on port? Does it matter?
And, this may sound dumb....but do the motors come with the inner gears set up for counter or do you just get a "lefty" shifter control that is reversed with the lefty prop on the motor?

 

[Wildcard]

Some are made to counter rotate some you just swap for a backwards prop.Port spins clockwise, Starboard, counter. You want the props pushing the wake aganst each other. Either way the shifter will work.

 

[Chuck Tribolet]

You need a counter rotating lower unit on one engine. The design of the lower unit
is such that if you run it in reverse all the time, the lower unit will have a short life.

http://continuouswave.com/ubb/Forum4/HTML/005053.html

 

[Wildcard]

Your link says exactly what I said and not what you are saying. SOME can run in reverse. I don't think any of the new ones do thou...

 

[cobaltblue]

Props spin out. Most lower units will not run very long in reverse at high RPMs. The way the lube is pumped through them is not as efficient if at all in reverse. Some I/Os can be run either way, outboards can't.

 

[cobaltblue]

Some are made to counter rotate some you just swap for a backwards prop.Port spins clockwise, Starboard, counter. You want the props pushing the wake aganst each other. Either way the shifter will work.

No offense but where did this information come from? On most hulls, inward turning propellers causes terrible cavitation. When we rig some go fast boats, we will turn the props in but they still cavitate at slower speeds. The only reason to turn props inward is if there is so much power that the water is getting sucked out and the transom is falling in a hole. The one exception is cats, it doesn't seem to matter much which way the props spin.

 

[Chuck Tribolet]

Your link says exactly what I said and not what you are saying. SOME can run in reverse. I don't think any of the new ones do thou...

The link discusses outDRIVEs that can run in reverse. The topic of this thread is
outBOARDs.

 

[Wildcard]

No offense but where did this information come from? On most hulls, inward turning propellers causes terrible cavitation. When we rig some go fast boats, we will turn the props in but they still cavitate at slower speeds. The only reason to turn props inward is if there is so much power that the water is getting sucked out and the transom is falling in a hole. The one exception is cats, it doesn't seem to matter much which way the props spin.

Just from watching them casualy. Not a boat rigger so if you say outwards, so be it. Im sure most I have seen are in thou. Would that not provide more stern lift?

IOvsOB, my bad. Still brain frying from jet lag.

 

[Hank49]

I talked with the dealer here and he said only 150 hp and up have left hand rotation models. So what happens with all the twin 60s and 90s I've seen? Is it just not that much power and it won't make much difference? I drove a twin 60hp, 25 foot skiff a few years ago and it hauled ***** but I don't remember anything squirrly about it. I presume both were right handed motors.

 

[Wildcard]

You will get some steering torque and it will turn easer in one direction. There are tabs on the motors to counter the torque. It's not realy a big deal, esp with smaller motors.