Duo prop question?

[jklein8388]

Hey guys I'm new to the forum and and first post. I have an 01 HPDI 200 2 stroke on a 23' Pro Line and I have little to no control when in reverse and I was thinking a duo prop would really help with my problem but I've only seen duo props on stern drives. Does anyone know if there is a duo prop kit that I can buy for my outboard? Thank you in advance for any help or advice you can give me

[rodbolt17]

Yamaha did make a twin counter rotating lower.
good luck finding one.

be to easy to learn how to back down.

my 21 seapro with a single F150 does well. a lot better than my 21 shamrock did.

[jklein8388]

Yamaha did make a twin counter rotating lower.
good luck finding one.

be to easy to learn how to back down.

my 21 seapro with a single F150 does well. a lot better than my 21 shamrock did.

Ok thanks. I've been on and operated boats pretty much my entire life and I'm pretty confident in my abilities to handle a boat. Not saying that I can't learn anything new because I know that I can but I don't think not knowing how to back it down is the problem. Thank you for the reply though

[boscoe99]

There is no reason that you cannot purchase and install a Yamaha contrarotating lower unit on your motor. There are several dealers in Texas and Louisiana that do this on brand new motors.

http://www.boats.net/parts/detail/ya...300-01-NA.html

[zenoahphobic]

contra?

before anyone else replies, I may not understand but I think the OP wants better thrust in reverse (suggesting a duo prop type thingy?)

Thus fitting a counterotating lower unit , and keeping his RH prop would do this admirably. BUT he will soon be posting about the same problem now appearing in forward!!!

Am I wrong?

[99yam40]

yep you are wrong
Have a look at the link Bosco put up it shows the 2 props and 2 shafts they are talking about

[boscoe99]

Backing up is completely different than going forward.

If a motor is mounted really high to optimize forward efficiency, then if and when the motor is in reverse water is directed into the back of the boat. Particularly if the boat is a deep V type.

I find that if I trim up higher than normal in reverse then the water is directed more downward, and underneath the boat, providing a bit better control.

But like learning a foreign language, it is all about practice, practice, practice.

[rodbolt17]

yep, some hulls with single engines back down way better than others.
my shamrock I could mostly back down as long as I needed the stern to go right.
Harry Shiffman,our local tow boat US capt, is the only capt I have ever seen that could make a 21 shamrock back anywhere he wished it.

[zenoahphobic]

Duo

yep you are wrong
Have a look at the link Bosco put up it shows the 2 props and 2 shafts they are talking about

I take your word that there is a dual prop leg, just that I could not find the picture in the Link and what looks like counter rotating. Maybe the price should have alerted me.
Going back to difficulty backing up:
It would be nice if manufacturers made outboards where the exhaust is diverted from going out through the prop. As I find that in reverse this air is passed over the prop blades causing ventilation and no bite; the more throttle compounds the problem further.
Yes the height of engine and tilt position all part of solution.
If actual thrust is not the problem but the boat simply does not want to turn, then it is to do with not enough rudder area on engine, and lack of sufficient keel on the boat.
A solution, which may not look good is to add a rudder. This can be mounted like a kicker motor and linked to your steering rod or on to motor.
This will also give you good slow speed forward steering, addressing to significant inadequacies not yet addressed by the outboard boat industry.
You could simply use a skiff/windsurfer keel that kicks up at speed, or simply is pulled up out of slot and stowed.
We have trim tabs, why not a vertical trim tab acting like a rudder and is automatically retracted when up on plane? A neat design and build is possible?

[boscoe99]

Try this link.

2005 DX150TLRD Yamaha Outboard LOWER CASING DRIVE 2B Diagram and Parts

It is not counter rotating. A counter rotating lower unit turns one propeller counter clockwise when viewed from the rear.

A contrarotating lower unit turns two propellers, one clockwise and one counter clockwise.

Propellers are designed to be used going forward 99% of the time. As a consequence they are marginal when used in reverse. It just comes with the territory. My Ford truck works wonderfully well going forward. Got four forward gears. Some have five or more. In reverse it is not worth a shit. One noisy gear to back up with.

[zenoahphobic]

contra

Try this link.

2005 DX150TLRD Yamaha Outboard LOWER CASING DRIVE 2B Diagram and Parts

It is not counter rotating. A counter rotating lower unit turns one propeller counter clockwise when viewed from the rear.

A contrarotating lower unit turns two propellers, one clockwise and one counter clockwise.

Propellers are designed to be used going forward 99% of the time. As a consequence they are marginal when used in reverse. It just comes with the territory. My Ford truck works wonderfully well going forward. Got four forward gears. Some have five or more. In reverse it is not worth a shit. One noisy gear to back up with.

I now see the picture, thanks (iPhone just showed what looked like normal legs not contra.)
Yes O/B prop blade design does not give enough consideration to reverse.
Now if they designed an outboard leg that rotates 360 degrees, this would be very nice. Would help push the boat in all directions, very usefull docking also.
Only negative (apart from cost) would be in its ability to rapidly rotate from reverse to forward - can't see one that would enable this process to occur as quick as a dog clutch.

[DennisG01]

I also need to trim up to get decent maneuverability in reverse. "Decent"... not "good". Don't be too quick to assume that you can't learn a new trick. If your tabs are deployed, that will hinder things as well.