MacGregorSailors.com

AYA 16 and I tested props Sunday, April 30 on his 2004 M model "A Gust A", still heavy-loaded from our last Catalina Trip
Sunny day, 70 degrees, 8 knots wind, less than 1' seas. Runs were made into the light wind.

This is the real world . . . .

Piranha 129C 3 x 12.25 x 9 pitch
Empty Ballast = 11.3 kts (13.1 mph) @ 6,800 RPM
Full Ballast = 9.6 kts (11.1 mph) @ 6,500 RPM

Michigan 3 x 12 x 10 (tested on my lighter M)
Empty = 15.5 kts (17.8 mph) @ 6,300 RPM
Full = 12.6 kts (14.5 mph) @ 5.900 RPM

Michigan 3 x 12 x 11
Empty = 13.6 Kts (15.6 mph)@ 5,600 RPM
Full = 9.7 kts (11.2 mph) @ 5,300 RPM


Michigan 3 x 12 x 13
Empty = 10.5 kts (12 mph) @ 5,000 RPM
Full = 8.5 kts (9.7 mph) @ 4,700 RPM

Mike, Piranha doesn't make a 10-pitch prop for our motors. They do make a 3 x 12 x 11, so I'm exchanging the 9s for these blades to test (Piranha blades can be changed on the hub). I was disappointed that we didn't haul ass with the low-geared 9-pitch prop, but apparently that's over the top of the efficiency / torque curve. I am keeping my Michigan 3 x 11. 75 x 11 pitch prop, and then we can test this one against the Piranha.

I would be happy if I could go 14 knots loaded, as running on the ocean empty isn't for me. When we went to Catalina, those E-tecs were 2 knots faster than me (see Upcoming Events Catalina Trip March 25-26). And it looks like the Michigan 10 prop that I exchanged for the 11 might have been the best setup, but that was not tested on AYA's heavier boat.

Where is the 15-16 knot speed (full ballast) that we were promised?

Mark

i ran an '02 Suzi 50 for 2 years on my X.
all i can tell you is my best results came with the 12" x 10 pitch or 12" x 11 pitch.

i preferred the 11 pitch on a lightly loaded/no ballast X as it got me to 6100 RPMs and nearly 18mph. the 10 pitch got to 6500 RPMs, but lesser speed.

my only suggestion is that whatever prop you use, make sure that it has large "dog ears" in order to maximize water surface area.
it almost needs to be a "pontoon" style prop.

remember, you are pushing a 3,000# boat with a small, undersized motor. you need to be at max RPMs at WOT, but still be able to "grip" the water.

i loved the quiet at slow speed that the Suzi 50 offered. i didn't like the top end speed results that a 50hp provided. it just wasn't enough for my needs.


Bob T.
"DaBob"
'02X w/ '04 90-TLDI

I have gotton 15 knots with my Merc 50 hp Bigfoot fully ballested.

But you have to ignore the 15 mph wind pushing me from the stern,

My lightly loaded 2002 did 22 mph (about 19 knots) with my Bigfoot 50 EFI...this is with the 14x10 Mercury prop

Now it is down to about 15 knots which I attribute to lots of stuff on board.

Is the BF the only motor that can take the 14 inch props at the 50 HP level??

Catigale wrote: Is the BF the only motor that can take the 14 inch props at the 50 HP level??

etec 40, 50, 60 powerhead takes a 14".
that's really a monster prop for a 40hp.

my tohatsu 90 tldi takes a 14".
a suzuki 140hp uses a 13.5-14".
that's how wierd it is...

my only suggestion is that whatever prop you use, make sure that it has large "dog ears" in order to maximize water surface area.

One of the better attributes of a four blade propeller, they maximize water surface area.
I have a 4 X 11.4 X 9.5 Solas on a Honda 50hp and I got 19MPH at WOT (6100rpm) last weekend on a medium loaded, clean, new waxed hull with empty ballast. There was not much in the way of wind so I just went out to test the clean hull. I didn't try full ballast, I'll do that this weekend.

The 14" props require a larger gearcase than used by most 50s, and usually have lower gear ratio as appropriate. The Mercury Bigfoot is so-named because it has that larger gearcase, as does the sister-model by Yamaha, the High Thrust. The ETEC is the only other 50 that I've seen with a 14" prop. That the same powerhead, down-rated to 40, still uses the larger gearcase ... rare but useful for a Mac. As mentioned earlier, the Mac needs a pontoon-style of prop, due to its large wetted surface area.

My dealer strongly suggested choosing the Bigfoot for its larger prop, but I also wanted EFI. Suzuki motors beyond the 50 horse, DF-60/70 and DF-90/115/140 use gearing and case appropriate for a 14" prop. The three main factors that drove my choice of a Suzuki-60 were the larger prop, EFI, and 25-amp charging capacity.

(Back in 1999, the Suzuki DF-60 was considered "dangerously oversized" on a 26X~!)

Terry,

Where did you get your prop?

Did you guys use the Michigan Wheel props with the Vortex interchangable hub? I had problems with a poorly designed front thrust washer for it and MW sent me another, which I never got to test. Don tells me he got 20 mph on his GPS unballasted with it. It was their 4-blade, 9" pitch, I forget the diameter.

--
Moe

Pete,
You can look up the dealers for your state at the Solas website

http://www.solas.com/products/propeller/propeller.htm

If you get one choose the Alcup 4 x 11.8 x 9 it is the best for the Honda 50.

Frank C wrote:
(Back in 1999, the Suzuki DF-60 was considered "dangerously oversized" on a 26X~!)

i still worry about the extra weight. that is, 335# plus.
although Mark Prouty is runnin' the 410# Suzi 140 on the rear end of his X and hasn't shared any problems with us.

it's funny because the salesman who sold me my X talked about the main attribute of his X being a lightweight 1990's 2-stroke 185# Johnson.

although, you probably saw Roger's remarks to me this week...

will probably increase the rating to a larger motor.


Bob T.
"DaBob"
'02X w/ '04 90-TLDI

Bobby T.-26X #4767 wrote: ... i still worry about the extra weight. that is, 335# plus.
although Mark Prouty is runnin' the 410# Suzi 140 on the rear end of his X and hasn't shared any problems with us.

Surely you jest ... doesn't your TLDI-90 spec at 315 pounds?
You can erase that difference in myriad ways ...

• - a kid;
  - a dog;
  - a large cat;
  - 3 gallons of gas;
  - a case of beer.

(I never carry beer aboard. My motor's already overweight -
can't afford to risk BECOMING overweight, too! )

Mark Karagianis,
I suggest you keep the MIWheel 10 pitch or swap back to it since it gave much better results than the 11 pitch. Note that the 11 pitch does not reach the bottom of your Suzuki DF50's required RPM range (5500 - 6500RPM) when ballast is full, and only barely makes it into the RPM range with ballast empty.
..
The Suzuki DF50 is an engine that loves to run at high RPMs, with 4 valves / cylinder and direct ignition it can run really smooth at higher RPMs and make the best power. My Suzuki dealer and Suzuki sales rep. told me that the DF50 would be happy to run 7000 RPMs all day without troubles or extra wear and that the over-rev limiter is set to 7250 RPMs. The Suzuki DF50 engine computer records time at speed ranges, but the top one is speed over 6000, so anything over 6000 is recorded as 6000.

I have also been searching for the right prop for my Honda 50 on a 2005M. The problem I am having is Ventelation, air being drawn down from the surface, when i am in turns with ballast empty or just motoring in small chop with ballast full. The transom design puts the motor so close to the surface and when you have ballast in the bow is down more than the stern. I know most people I have talked to with 's are having the same problem. I am wondering if a smaller diameter is better, possibly the 4 blade like Terry runs. Anyone else solved this problem.

Frank C wrote:

Bobby T.-26X #4767 wrote: ... i still worry about the extra weight. that is, 335# plus.
although Mark Prouty is runnin' the 410# Suzi 140 on the rear end of his X and hasn't shared any problems with us.

Surely you jest ... doesn't your TLDI-90 spec at 315 pounds?
You can erase that difference in myriad ways ...

• - a kid;
  - a dog;
  - a large cat;
  - 3 gallons of gas;
  - a case of beer.

(I never carry beer aboard. My motor's already overweight -
can't afford to risk BECOMING overweight, too! )

Frank C...
i guess i didn't make myself clear.
what i'm saying is that i worry about the weight above the 200# threshold.
remember, when the X rolled out in 1995, the tohatsu 50 (what? 165#?) was on the rear end.
then by 1998 or so, the honda 50 (205#) was the engine of choice.
then by 2002, it was either suzuki 50 or more (250# plus).
all this time it's basically the same undersized trailer.

now i've got 315#, you've got 335#, Prouty's got 410#. still on the same undersized trailer where 1/4 of the boat (with engine) overhangs the rear.

alot more weight now (when trailered) then when it was first designed.
that's all i'm saying.
it keeps me awake at night.