lots of yaw at high speed under power

[BOAT]

I honestly don't have a clue. It has three blades and it is black.

Hey! That's the same prop I have!

[Tomfoolery]

I honestly don't have a clue. It has three blades and it is black.

Hey! That's the same prop I have!

Maybe that's my problem. My black one has 4 blades, and my 3-blade is gray. So I should either paint my gray one black, or cut a blade off my 4-blade.

fouz: The blade specs are stamped on the hub, usually on the outside, but sometimes on the ends where you can't see it unless you take it off. Unless you knew that already.

[bscott]

I don't know if the steering on the is the same as the but I watched my grand daughter steer my and she over steered the wheel resulting in a slalom course. The Macs are very sensitive to over steering and the slop in the system adds to the problem.

Bob

[fouz]

I honestly don't have a clue. It has three blades and it is black.

Hey! That's the same prop I have!

Maybe that's my problem. My black one has 4 blades, and my 3-blade is gray. So I should either paint my gray one black, or cut a blade off my 4-blade.

fouz: The blade specs are stamped on the hub, usually on the outside, but sometimes on the ends where you can't see it unless you take it off. Unless you knew that already.

Ya, I was just wondering about his prop. Im running a 14x11 ATM but only getting 5200-5300 lightly loaded. More people and gear this weekend I only got max 5000 rpms. Just trying to make my mind up if the next prop is going to be a14x10 or a 14x9.

The PO had what I was told (not by him but an outboard dealer)was a 14x9 but I can't be sure and it didn't work good at all. Max rpms and plowing was all it did. So I'm thinking 14x10 or I was told the wrong prop size on the original.

[kurz]

Ya, I was just wondering about his prop. Im running a 14x11 ATM but only getting 5200-5300 lightly loaded. More people and gear this weekend I only got max 5000 rpms. Just trying to make my mind up if the next prop is going to be a14x10 or a 14x9.

The PO had what I was told (not by him but an outboard dealer)was a 14x9 but I can't be sure and it didn't work good at all. Max rpms and plowing was all it did. So I'm thinking 14x10 or I was told the wrong prop size on the original.

Hello
I have 26m/mercury 60HP, 14/11, but does not go till 5000rpm. My dealer want give me an 14/9. Does exist 14/10 for mercury or not? Thanks

[fouz]

Don't know about the mercury but I know iboats.com has 14x10 for the Yamaha.

[Tomfoolery]

iboats shows both a Michigan Wheel and a Quicksilver 14 x 10" 3-blade for the 60 hp Bigfoot.

[Crikey]

Ya, I was just wondering about his prop. Im running a 14x11 ATM but only getting 5200-5300 lightly loaded. More people and gear this weekend I only got max 5000 rpms. Just trying to make my mind up if the next prop is going to be a14x10 or a 14x9.

The PO had what I was told (not by him but an outboard dealer)was a 14x9 but I can't be sure and it didn't work good at all. Max rpms and plowing was all it did. So I'm thinking 14x10 or I was told the wrong prop size on the original.

Hello
I have 26m/mercury 60HP, 14/11, but does not go till 5000rpm. My dealer want give me an 14/9. Does exist 14/10 for mercury or not? Thanks

Kurz, I can't tell you which manufacturer has what specific prop, but the weight and resistance of your boat should be offset by the grab of the particular prop to end up no higher than the red line of your engine at WOT.
Your pitch/diameter combination sounds low. Remember, it's different for each class of boat - hull, particularly with a Mac that planes. Within what works for preserving the engine is either more thrust at low rpm's or high rpm's.
R.

[DaveB]

I have a new 50 big foot with 14x10x3 triple cup blade and needs the pitch down to 9.
All depends on the pitch and cup.
I will take my prop down to local Boris and recup and reduce diameter 1.5 degrees.
My rpms top are 4800 , was 5100 rpms.
As new went from 17mph in a heavy loaded empty ballast to 14mph and top 4800 rpm empty ballast.
This is on a new 50 hp bigfoot.
Those who have cups built in is probably ok for a 1-2 cup change.
Just be assured that making a change to get your rpm's in the RPM range. Full charge of 18 amps .

Dave

iboats shows both a Michigan Wheel and a Quicksilver 14 x 10" 3-blade for the 60 hp Bigfoot.

[beene]

Smokin M

http://s166.photobucket.com/user/beene_ ... 3.mp4.html

G

[Crikey]

Smokin something!

R.

[WASP18]

I guess a good rule of thumb is to remember that the rudders and board are designed for sailing speeds. In a power mode at speeds above sailing, all "boards" are retracted except for the centerboard at barely 3 to 4 inches to enhance steering and straight-line stability. My experience this weekend was dealing with enormous wake generated from the over-powered boat crowd blasting along at record speeds along with record setting gas sucking consumption. I can't imagine operating a Mac without water ballast under these conditions. Blue skies and heavy seas.

As wake approached us parallel to our heading and if I didn't turn in time to head perpendicular into the wake swells, we would rock vigorously as if in a brief storm. Never a dull moment.

[Highlander]

Here's Beene showing off again
http://s844.photobucket.com/user/TheHig ... 2.mp4.html

J

[Highlander]

Beene & I just fooling around
http://s844.photobucket.com/user/TheHig ... 2.mp4.html

J

[BOAT]

Here's Beene showing off again
http://s844.photobucket.com/user/TheHig ... 2.mp4.html

J

I notice he is standing right behind the helm - did he get wet?