Which Prop with the Tohotsu 6 hp Motor

[Aldo]

I finally saved up enough money to replace my (very reliable) '79 Johnson 6 hp 2 stroke motor. I plan on purchasing a Tohotsu 6 hp long shaft. My son has one on his C-22, and he actually uses 1/3 as much gas as I do, and this is not an exaggeration. It's not the savings from the cost of the gas that's the issue, it's just that he doesn't have to worry about running out of gas all the time, or carring 12 gallons of gas in his boat.

But that's not my question. My son has the 7.9 dia. by 6 inch pitch propeller on his motor that he got with his "extra long" shaft motor. I don't need the "extra long" shaft, the "long" shaft should be fine for my boat. But, the long shaft motor only comes with a 7.8 inch dia. by 8 inch pitch propeller. I will, of course, be ordering a lower pitch propeller. When I e-mailed the seller he replied that most sailboats use a 6 inch pitch propeller called an "elephant ear" propeller. Have any of you used this "elephant ear" propeller, and do you have any comments about it.

The thrust of my son's motor is really impressive when moving the boat around the slip. When I put my motor into reverse, all it does is make smoke and noise, and eventually the boat will start to slowly back out of the slip. With his motor, you better hold on when you shift it into reverse.

Thanks for your comments, Aldo

 

[Bilbo]

Hi Aldo, One thing that I noticed about my old Yamaha 6 is that the depth of the prop can make a difference. Especially when backing up the thrust of a shallower blade will just hit the transom more.
As for props pitch. This is going to effect the "pickup" like the gears on a car. So will the amount of surface area of the prop, and prop RPM speed. Of course like gearing in vehicles, one with a shallower pitch will get her moving sooner and with more umph but the top end will be slower.

http://continuouswave.com/whaler/reference/prop1.html

 

[Ken]

Hi Aldo,

I have the 5hp Nissan (same motor as the Tohatsu or Mercury all made by Tohatsu) as the 6hp your looking at. Mine came with the 7.9X7.9 standard prop used on both the 5hp and 6hp at the time. (2004) It replaced a 4.5hp Evinrude that like yours loved the fuel. The 5hp is a miser on fuel, although I carry an additional 3 gal when cruising I have never needed it.

I gave great thought at first when I bought the motor having gone through exactly what you say about your current motor. I found all my fears to be unfounded, the standard prop has proven to be fine. It will stop the boats forward progress in her tracks when put in reverse with little or no effort, something the Evinrude would not do. In fact it wouldn't even slow it down although it did have the heavy boat prop.

One other thought, you might want to check out Practical - Sailor on there report on the 6hp before you pay the difference over the 5hp for the 6hp. I can say nothing against the Nissan it has performed flawlessly. My only complaint came after I added the stern rail. (that of course was no fault of the motor) I found I could no longer get it out of reverse easily. The fix was easy, a gear shifter was added.