2-speed Outboard? Anybody Seen This Before?

[FishNette]

So, now that we have our flounder boat in the water, I'v been trying different propellers to find the one that best suits our set-up. In my quest, I ran across a Land & Sea Torque Shift propeller. We ran it a little yesterday, but still need to tweek on it for optimum performance.

It actually changes from a shallow 15" pitch to a much steeper pitch. We were running 7000 rpm wot and when it shifted we dropped to 5000 rpm. It sounded like a transmission shifting gears. We'll be tuning on it more this week. The top end pitch is way too much. It has limitting screws to reduce the pitch after shifting, so we will be adjusting those.

Just wanted to share this find with you. Have any of you tried one before??

[Robalo]

Nope, never even heard of one.

[duckboy007]

My outboard has two speeds too, ON and OFF.

That is a cool concept, how does it know when to shift pitches?

[Curmudgeon]

Very cool. Never heard of them but it makes sense.

[evansmarine]

Be careful, heard of them as well as people over reving their motor and blowing them before it shifts.

[coachlaw]

In the voice of the Comic Book Guy

"Coolest idea EVER."

But can it actually work right?

I've often wondered why marine engines don't have transmissions with more than one gear.

[FishNette]

Be careful, heard of them as well as people over reving their motor and blowing them before it shifts.

My thoughts exactly, Bryan. Our "top fuel" outboard redlines at 7200 rpm, but hearing it scream at 7000 made me cringe. Being the mechanically inclined person that I am, I am always a little leary of these type gadgets. I'll try it a few more runs, but if it doesn't do what I want, it'll become garage art on my garage wall.

[JHardgrave]

Airplanes do something similar using oil pressure to vary prop pitch.

[FishNette]

Airplanes do something similar using oil pressure to vary prop pitch.

Ya, if it could be controlled that would be optimum. At least on or off.

[Williep]

I found a video about this prop if it's the same one.

http://www.youtube.com/watch?v=C5niXCY-ikM

[FishNette]

Update: We made a few runs yesterday evening across Clear Lake. I've determined how to make it shift easily. It just has to be a little 'free' near the surface. Once you get on plane, just start raising the jack plate and it shifts when the prop breaks the surface. Easy enough. Setting it to the optimum pitch was easy enough as well. A simple twist or so of the t-handle allen wrench to limit the top end blade pitch. It did make the top speed better than it has been. 51.4 mph.

I like the theory of this prop, but at slower speeds, like in no wake zones, it rattles and makes noises that I associate with mechanical problems. For that reason, it will be removed today and displayed on my garage wall for conversational purposes.

I have a 4 blade, 21" pitch prop that will do the same thing, without all of the nerve racking noises at slow speeds.

[Rollo]

Its a great idea but caution is the word,The shift point needs to be fine tuned also!!

[Curmudgeon]

Darn. Cool idea though.

[evansmarine]

have a customer that is intrested in your prop if you want to sale it.

[FishNette]

have a customer that is intrested in your prop if you want to sale it.

I'll trade it for a good stainless 4 blade 17" pitch prop