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11 August 2005, 15:47
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#1
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Member
Country: UK - England
Town: London
Make: Solent
Length: 6m +
Engine: Mercury 150 Optimax
Join Date: Feb 2005
Posts: 13
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New Props for 150 Optimax
I am looking for new props for my 150hp Optimax.
Currently running a 19" Laser II, looking for:
a) Something to get more speed
b) Something for more grip in tight turns and pulling up skiers etc
Aware that this will be two different props.
Advice and sellers wellcome.
Many thanks,
James
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11 August 2005, 15:48
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#2
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Member
Country: UK - England
Town: Exeter
Boat name: TomBuoy
Make: Solent
Length: 6m +
Engine: Mercruiser 1.7dti
MMSI: 235 020 387
Join Date: Oct 2003
Posts: 1,073
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What rev's are you pulling at WOT with the 19" prop?
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11 August 2005, 15:58
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#3
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Member
Country: UK - England
Town: Bucks
Boat name: My Buoy & Ding Dong
Make: Ribeye,SR4 & Bombard
Length: 6m +
Engine: 115,50 & 15Hp Yams
Join Date: Feb 2004
Posts: 2,078
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What speed are you getting at the moment?
Give Julie a call at steel developments, very help full!
http://www.steeldevelopments.co.uk/
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11 August 2005, 16:03
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#4
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Member
Country: UK - England
Town: London
Make: Solent
Length: 6m +
Engine: Mercury 150 Optimax
Join Date: Feb 2005
Posts: 13
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Getting about 5500 revs fully trimmed and can make 46 knots with 4 in the boat, looking to go above the elusive 50 barrier!!
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11 August 2005, 16:07
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#5
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Member
Country: UK - England
Town: Bucks
Boat name: My Buoy & Ding Dong
Make: Ribeye,SR4 & Bombard
Length: 6m +
Engine: 115,50 & 15Hp Yams
Join Date: Feb 2004
Posts: 2,078
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Quote:
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Originally Posted by jimc
Getting about 5500 revs fully trimmed and can make 46 knots with 4 in the boat, looking to go above the elusive 50 barrier!!
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Clean & wax the hull , kick 3 people out!
Job done & saved £600 on new props
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12 August 2005, 08:32
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#6
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Member
Country: UK - England
Town: Margate / Ramsgate
Boat name: Magellan Echo
Make: Ribtec
Length: 9m +
Engine: Yanmar 315
MMSI: 235086143
Join Date: Feb 2002
Posts: 1,601
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My Opti 150 max'es out at 5750, so you are not far off. The solent hull has a reputation for being quick but i'm not sure 50knts is attainable with a 150. Are you trimming right out to get these rev's?
I don't know a huge amount about different props but my simplastic view would say try a 17" laser II, try and borrow one if possiable. I don't have one i'm afraid.
I can make 46knts with a 21" laser II @ 5200 RPM and the same speed @ 5500 RPM with a 19", never tried a 17" so please report back if you try it.
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12 August 2005, 10:51
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#7
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Member
Country: UK - England
Town: Mighty Penryn
Boat name: Little Joe.
Make: Avon Searider
Length: 4m +
Engine: Honda BF50
Join Date: Aug 2005
Posts: 6,047
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Props
If your pulling 5500 rpm and the opti maxes at 5750 then more speed cant be obtained. To gain the extra 250 rpm you'd need to fit either a smaller prop or one of a lesser pitch. This will give better pull out but less speed. Another trick is to lightly sand the hull with some fine wet and dry paper. 800 grit with soapy water is good. The top dinghy racers do this, it causes the hull it ride on a layer of minute bubbles which "releases" the hull and reduce drag. Waxing the hull tends to do the opposite and create suction between the hull and the water. It sounds as if 46 knts might be yer lot though.
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12 August 2005, 11:06
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#8
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Member
Country: UK - England
Town: Bucks
Boat name: My Buoy & Ding Dong
Make: Ribeye,SR4 & Bombard
Length: 6m +
Engine: 115,50 & 15Hp Yams
Join Date: Feb 2004
Posts: 2,078
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Quote:
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Originally Posted by Mollulnan
If your pulling 5500 rpm and the opti maxes at 5750 then more speed cant be obtained. To gain the extra 250 rpm you'd need to fit either a smaller prop or one of a lesser pitch. This will give better pull out but less speed. Another trick is to lightly sand the hull with some fine wet and dry paper. 800 grit with soapy water is good. The top dinghy racers do this, it causes the hull it ride on a layer of minute bubbles which "releases" the hull and reduce drag. Waxing the hull tends to do the opposite and create suction between the hull and the water. It sounds as if 46 knts might be yer lot though.
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So a sandy bottom goes faster hey
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12 August 2005, 13:54
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#9
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Member
Country: UK - England
Town: Mighty Penryn
Boat name: Little Joe.
Make: Avon Searider
Length: 4m +
Engine: Honda BF50
Join Date: Aug 2005
Posts: 6,047
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Sandy bottom
....may give you a rash also!
Quote:
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Originally Posted by Nick Hearne
So a sandy bottom goes faster hey 
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12 August 2005, 13:56
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#10
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Member
Country: UK - England
Town: Margate / Ramsgate
Boat name: Magellan Echo
Make: Ribtec
Length: 9m +
Engine: Yanmar 315
MMSI: 235086143
Join Date: Feb 2002
Posts: 1,601
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My osprey is anti-fouled, often wondered how much this knocks the top speed.
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