Help! Zodiac Futura Mk2 - Yamaha 50H Prop Pitch???

[ZodiacFuturaMk2]

I have just purchased a new 2007 Zodiac Futura MK2 HD and installed a 1999 Yamaha 50HML two stroke long shaft outboard with manual start, gas assist manual tilt (just under 70kg I think)

This outboard is fitted with a 10 3/8 x 13" prop.

At full throttle this very lightweight boat (4.1m long & 100kg) does 30mph. In the 1998 Zodiac brochure it stated the Futura Sport (white and yellow) which was a much heavier boat did 60mph with the same 50H!!!

This new outfit that should be superb isnt even as good as my old 96' Futura with a 30Hp yammy.

So three questions:

1) What pitch prop for max speed???

2) What pitch prop for skiing / wakeboarding???

3) What height should the outboard be mounted?? At the moment the Anti Cav plate is in line with the bottom of the transom / hull.

Many thanks

Gareth

p.s. I have no idea what revs the engine is running as it is very basic and has no speedo / rev counter!

[Nos4r2]

What pitch prop do you have at the moment?

[Jelly]

Hi Gareth
I used to have one of the HD versions of this boat and I also had the cavitation plate level with the bottom of the hull.
The problem we found was that it accelerated fine while the boat was lifting on the hull, once the boat stated to lift onto the futura hulls (the extra inflatable tubes like runners on the underside of the main tubes), we got ventilation.
Once this last lift happened the prop was lifted out of the water causing the Ventilation. If you can I would lower the engine so that the top of the ventilation (cavitation) plate is level with the bottom of the Futura tubes. This will allow you to get all the power of the engine in to the water and not to Ventilate.
I would also look at the steering ram installation the zap cats have because hand steering a 50Hp on a light boat will kill your arm quickly !
I miss my old zodiac for the fun side but not for the arm ache from holding that yam 50 !
good luck
James
Just looked at your picture and can see your steering is not hand held so the zap cat comment is no use.

[ZodiacFuturaMk2]

The Prop Pitch is 10 3/8 x 13" at the moment

Also the new redesigned futura has much larger main tubes, speed tubes and the keel is much lower and acts like a third speed tube so I guess the anti cav problem isnt so bad now!

Cheers for your replies

Gareth

[ZodiacFuturaMk2]

Anyone - know what prop to put on this engine to get higher speed?

[fast fred]

Stainless 15-16 " of pitch, cupped, thinkin that hull should have a 15" shaft
not a 20"

jack it up one hole at a time she what she dose, watch your water psi

[ZodiacFuturaMk2]

Many thanks fast fred

The new futura Mk2 takes a long shaft for some reason - bigger tubes I guess.

What do you mean by psi? - Its now mounted at max height and still doesnt cavitate.

Cheers

G

[fast fred]

looks to deep from hear. some basic rules for getin it to go fast on the water.

1) rule number one is, to go fast on the water you Must get the hull Out of the water.
your hull dose this on it's own cuzz it's air intrapment style.
2) drag, got to get rid of it.
the prop, from 12o'clock back around to 12o'clock, or one turn of the prop,
from 4:30 to 6o'clock is all the power to push the boat, no mater what.
from 6 o'clock back around to 4:30 is All drag, to get rid of it you serface the prop.
thare is a fine line between cav', runnin it out of water bein to high for that style pick up.

13" of pitch is too short on that hull.

[fast fred]

jack plate

[ZodiacFuturaMk2]

Right ive taken some more photos of where the engine is mounted in relation to the bottom of the transom, keel and speed tubes. Any comments welcome. I just took the boat out - it was rough conditions but it didnt cavitate even in sharp turns. I just it could do in calm conditions if I got it right up onto the speed tubes, Im not sure.

As said before the prop I have at the moment is a Yamaha Aluminium 13 pitch I think I will try same prop but a 10 x 15 Lip Cup - sound better??

Many thanks

Gareth