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Old 15-02-2009, 10:55 AM   #1
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18ft phantom

Hi Guys and Girls

Need to pick your brains, Got 18ft phantom had transom beefed up to 4" wide 28" high I am putting my 225 yam on the back, is the transom too high for my 24" chopper prop, as the four bolts that hold the engine on are in the well, will it make any difference? I have also got an extra water pick up on the gearbox that works well. and the water pick up is on the boat.

regards speedygirlie
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Old 15-02-2009, 11:23 AM   #2
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phantom 18

too high needs to be about 25-26 inch high on transom. phantom boatsr like the torpedo to run about 1.5 inch below boat hope this helps
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Old 15-02-2009, 12:15 PM   #3
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Would having a big 225 yam that high up on a P18 not cause stability issues? What is the length of the leg on your yam?

James
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Old 15-02-2009, 07:22 PM   #4
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Country: UK
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Boat make: ring 20 c
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18ft phantom

Cheers for the info guys,

its a standard leg on the yam James

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Old 16-02-2009, 01:18 PM   #5
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We run our 18's with the bullet of the box almost level with the transom. Most the people on this site won't agree with that but after trying every position on a hydraulic jack that gave best lap times.
24 chopper will run fine as that is what i use for racing.
Don't go any higher though as you'll be able to slide the back of the boat which is pretty good fun but not ideal if racing.
My expeience is all with a transom jack so if your mounting direct to the boat you may need to go a bit lower than the V to get good water pressure.

Hope this has helped some.
Will
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Old 16-02-2009, 06:15 PM   #6
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Quote:
Originally Posted by speedygirlie View Post
Hi Guys and Girls
transom beefed up to 4" wide 28" high
Quote:
Originally Posted by speedygirlie View Post
Cheers for the info guys,

its a standard leg on the yam James

Cool, well IIRC, the length from the top of my saddle to the bullet of my gearbox is 29" (mine are std shaft too). On a 28" transom that will leave you with the bullet an inch below - about perfect if the engine is bolted to the transom
I could be wrong, but i seem to remember a good guide being that for every 6" you go back with a standoff bracket or lifter, come up an inch, which would tally with willwood's findings too.
Chopper prop will be just fine at this height, and is said to be a good prop for a phantom (i wouldn't know, i've never owned one )
As for it being ok for all 4 bolts being in the well, that's all down to how good the transom strengthening is. I would expect there to be knees glassed in to give the top of the transom some more support? Other people on here know waaaaay more than me about that kinda thing!
On a seperate note, I'd double bolt the saddle to the boat, I've heard plenty of stories about the saddles snapping on yams, mine have various plates welded to them for strength!

I'll stop rambling now!

James
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Old 16-02-2009, 06:30 PM   #7
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Country: UK
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Boat name: fast'n'loose
Boat make: ring 20 c
Engines: merc 150
Cruising area: River Mersey

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Posts: 24
18ft Phantom

Hi James

Thank you so much for the information, it does help ALOT !!

Regards

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Old 16-02-2009, 09:31 PM   #8
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Glad to be of assistance, it's all one big learning curve for all of us!

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Old 16-02-2009, 10:09 PM   #9
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Country: UK
Location: Lancashire
Occupation: chief cook and bottlewasher
Interests: Fast boats and fast men
Boat name: fast'n'loose
Boat make: ring 20 c
Engines: merc 150
Cruising area: River Mersey

Join Date: Feb 2008
Location: Lancashire
Posts: 24
18ft Phantom

Hi Will

Thank you so much for your information, every little helps!!

I think we have got it sorted now, Ste Hutch said the same as you.

Regards Speedygirlie
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