Yet another propellor question!!!

[Ring Owner]

At the moment I am running a 23P, 14" Diameter (or 13 and abit) stainless prop on a Merc 150 XR2, all rigged up to Ring 18. Getting a good top speed (65MPH on the last outing and not exceeding the maximum recommended revs of 5500RPM) but it doesnt seem ideal for general recreational ski-ing and larger water toys.
Well be truthful, its fine for a "normal" person and pulls the kids a treat but pulling a 6ft 6", 13stone mono-skier out of the "hole" seems to be a problem - great when I am up but slow to get there.
Was recommended dropping down to a 19" pitch (same diameter) but would rather have some feedback before I splash out on another prop.
Anyone help me out?

[roofer]

Get yourself a high five prop great for skiing and acceleration

[Ring Owner]

Cheers - any thoughts on size and pitch?

[mike k]

I just happen to have a High Five for sale that would fit. I think its a 23 but I'll check when I get home if you're interested.
It worked really well on my previous boat (Signature 1900ss/Seaquel)

[Matt]

Pretty sure the max recommended revs on the old 150 xr2 (mid 80's) is 6000. The standard 150 & 200 were 5500 rpm. So you could afford to drop pitch to a 21 which would improve acceleration and still keep the revs at full throttle within spec.

[Ring Owner]

Mike, sorry for what may be an obvious answer but would there be a noticable difference between a High Five 23P and a 'standard' 23P? What type of price would you be looking at if you sold your one?

[cfun]

I have a ring hulled rib, and have a 23p 5 blader running on an xr2 it's a good combination I have found for water sports of all types and top speed was not altered ( thats cus I cant reach top speed )

[Matt]

IMVHO, if you're already turning 5500 flat out, on a high 5 of the same pitch I think revs would be too low.

I would look at a 21" version of your current prop (guessing laser 2 or similar), or probably a 19" Hi 5.

Originally posted by Ring Owner
Mike, sorry for what may be an obvious answer but would there be a noticable difference between a High Five 23P and a 'standard' 23P? What type of price would you be looking at if you sold your one?

[mike k]

I checked when I got in and it's a 21 High 5. I'm looking for £200.

[1up]

i've been advised if your prop is good with a 3 blade, then a 4 blade will give you the pull you need like a trophy plus, I guess a hi five would be worth a try. But I think a 19 will be way way too small so a 21 would be a 3 blade alternative. But one good piece of advice I was given is to try everything that you can get your hands on

[cfun]

Just as a thought 65MPH on an old XR2 with a 23p does seem odd, I had an old xr2 on a 19.6 ft Marshan years ago it ran 65-66mph on a 26p ex race prop that had been modified, when I fitted a 24p I assumed it would accelerate quicker and over rev, this did not happen the revs droped to 6000 from 6300 and speed fell to 59-60 MPH, it's all in the prop, the problem with the 26p it was no good for water sports it just slipped and ventilated, a 23p high 5 was perfect although outright speed was considerably lost

[jw.]

Originally posted by Matt
IMVHO, if you're already turning 5500 flat out, on a high 5 of the same pitch I think revs would be too low.

I would look at a 21" version of your current prop (guessing laser 2 or similar), or probably a 19" Hi 5.

Agreed, I'm with Matt on this one.

[Ring Owner]

Mike K,
Tried to PM you earlier but your box is full - sent email instead

[BluFin]

Ballpark Numbers Outboards
Increasing / decreasing pitch by 1" will change RPM by 150-200 rpm +/-
Moving from a 3 to a 4 blade expect to see a drop of 100 rpm Approx

Only ballpark numbers not tablets of stone
its very much a suck it and see but summing up 4 blades over 3

1/planes boat faster than 3-blade propellers
2/keep the boat on plane at a lower speed
3/give improved mid-range speed at the same rpm as a 3-blade propeller
4/provide quicker acceleration than most 3-blade propellers
5/run smoother than 3-blade propellers
6/have better holding power in rough conditions
7/are less likely to ventilate in sharp turns
8/provide better low speed handling
9/SLOWER than 3 blade propellors

[GrahamF]

The Mercury Tempest plus prop seems to work quite well on my Ring hull, with an Optimax mounted fairly high on transom (don't have exact measurements). On my boat this prob helped reduce the tendancy to chine walk, and a good compromised between resisting cavitation in turns, top speed and grip when getting on the plane.

see .Mercury Racing's website for details for details

They can be purchased at reasonable prices from from the States via ebay.com