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Old 31-08-2016, 10:41 PM   #1
oxo
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Country: england
Location: isle of wight
Occupation: stonemason when the water's too rough!
Interests: boats engines beer
Boat name: outlaw
Boat make: marshan 18/crusader 17
Engines: merc xr2/ merc115
Cruising area: solent/round island if i got enough fuel!

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Location: isle of wight
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opti 200 prop choice?

Hi all,

Can anyone recommend a good prop choice for a 3l opti 200 on the back of a marshan 18? bullet is going to be roughly 100mm below vee with a dual water pick up box(not sportmaster, cle etc) Need good speed but not too much torque!
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Old 01-09-2016, 02:26 PM   #2
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Country: Finland
Location: Helsinki
Interests: Everything fast
Boat make: Hydrostep 650, TG 5000XR, Kimach 450 Speed, Stopper
Engines: Merc 115 ProXS 4S, Merc 60 Formula Race, Yamaha 20
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Join Date: Apr 2014
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Posts: 67
Before someone comes and suggests a Laser II... why would you want to bury the engine so low?

I must say I haven't ever propped a Marshan but assuming it's rather similar to Phantom and Ring I would go with a slightly bow lifting prop capable of running also close or at the surface.

Personally I would invest a few hundred quid on a manual lift to be able to adjust engine height based on conditions. As an overall sporty and speedy pleasure prop I would first test Trophy Plus and Tempest from the Mercury line up, most likely in the 25-27" pitch range, this is with the prop rather close to the surface. From the after market props I would consider Turbo TXP, both 3 and 4 blade, Solas Scopion and Hydromotive 3 and 4 blade props. Some have also had succes with 4-blade Ballistic as well.

These are just the ones that have worked on the Phantoms and Rings I know. Personally I have always ended up with a 4-blade Hydromotive. Not necessarily the ultimately fastest prop but suits very well my driving skills and preferences. The prop question is one of the eternal questions and is a matter of choise. Others might have differing opinions
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Old 01-09-2016, 07:32 PM   #3
oxo
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Country: england
Location: isle of wight
Occupation: stonemason when the water's too rough!
Interests: boats engines beer
Boat name: outlaw
Boat make: marshan 18/crusader 17
Engines: merc xr2/ merc115
Cruising area: solent/round island if i got enough fuel!

Join Date: Oct 2008
Location: isle of wight
Posts: 208
prop choice

Thanks Carrera,

I'm just a bit worried about the extra weight on the transom. It's a pretty old boat nowadays and the opti is already 60 odd kilos heavier than my XR2. Plus the higher the engine on an 18foot boat is gonna up my centre of gravity. Ive got a land & sea hydraulic lifter but too frightened to put it on cos there'll be a third of a ton hanging off a 20 odd year old transom. ooer!
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Old 01-09-2016, 09:04 PM   #4
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Country: Finland
Location: Helsinki
Interests: Everything fast
Boat make: Hydrostep 650, TG 5000XR, Kimach 450 Speed, Stopper
Engines: Merc 115 ProXS 4S, Merc 60 Formula Race, Yamaha 20
Cruising area: Helsinki

Join Date: Apr 2014
Location: Helsinki
Posts: 67
You might be on to something

It is true that most of the Marshan, Phantom & Ring transoms are starting to be history. And as you pointed out, they were initially built for engines in the 170kg range, not for 230kg. I have the same issue on my 20 year old Phantom 21. It's just a matter of time when the transom needs to be replaced.

... if you decide to go with a lift, a Bob's Manual jack is about 12kg, so will it break the transom... you don't know before you try
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Old 26-09-2016, 07:35 AM   #5
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Quote:
Originally Posted by Carrera View Post
Personally I have always ended up with a 4-blade Hydromotive.
Hi Carrera I'm very curious which hydromotive prop you then end up with? I presume either the Quad IV O/T or the Quad IV-X O/T (the bow lifter version)? I'm always afraid that the Quad IV O/T will not produce enough bowlift.

I agree with Carrera that a jackplate would be necessary to achieve proper motor height. I personally think the boat will not drive well with the propshaft 100mm below. With a 3.0L 200 on a 18ft I would also invest in proper steering and solid mounts.

As for props, I think Carrera is in the right direction suggesting Trophy Plus and Turbo TXP props for general use. Mercury pro ET will also work good probably. I think the Trophy Plus will be most easy to find.
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Old 26-09-2016, 07:55 AM   #6
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Country: Finland
Location: Helsinki
Interests: Everything fast
Boat make: Hydrostep 650, TG 5000XR, Kimach 450 Speed, Stopper
Engines: Merc 115 ProXS 4S, Merc 60 Formula Race, Yamaha 20
Cruising area: Helsinki

Join Date: Apr 2014
Location: Helsinki
Posts: 67
Quote:
Originally Posted by Roy_E View Post
Hi Carrera I'm very curious which hydromotive prop you then end up with? I presume either the Quad IV O/T or the Quad IV-X O/T (the bow lifter version)? I'm always afraid that the Quad IV O/T will not produce enough bowlift.

I agree with Carrera that a jackplate would be necessary to achieve proper motor height. I personally think the boat will not drive well with the propshaft 100mm below. With a 3.0L 200 on a 18ft I would also invest in proper steering and solid mounts.

As for props, I think Carrera is in the right direction suggesting Trophy Plus and Turbo TXP props for general use. Mercury pro ET will also work good probably. I think the Trophy Plus will be most easy to find.
The one that has worked best for me on a P21 is Hydromotive Quad IV X O/B SST 15" / Group A+. It is not the fastest prop but the best overall prop that is also easy to drive in the 80+ mph range. Personally I prefer a prop that is smooth to drive at wot for longer periods rather than a prop that allows high peak top speed but is tricky to drive. Most often that is also faster in racing in the end.
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