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Old 20 April 2010, 23:05   #1
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Country: UK - England
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Boat name: Sparrowhawk
Make: Osprey
Length: 5m +
Engine: Yamaha 90hp 2T
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Mid shaft 17" 40hp on a searider sr4 help about transom cut??????

this is my first post on here and i need some advice..... i have searched through this forum for some time now meaning to join and post a progress report but never seem to get time. anyway... my issue.
i brought the boat the end of last year and have spent the winter replacing the transom as well as re painting the hull and fitting it out as i wanted it. i had a long shaft 25hp yamaha autolube engine that i fitted and tried out 2 weeks ago but decided i loved the boat but wanted a bit more up and go for when mates are on it so looked around for a 40hp and last night i went and got myself a 1998 mariner 40hp ex navy engine hardly used but being over excited and not paying attention realised today that the engine is to short for my transom. my question is what are people oppinions to cutting the transom down by roughly 3" and fitting the engine then, would this be ok? from looking at the waterlines even with the slight more weight the water line shouldnt go over the top of the transom but would just mean need to take more care when slowing down and making sure i turn etc. i have no issuses with doing the work on the boat as its virtually been rebuilt anyway just dont want to go cutting away when it could cause serious issues?

please help

thanks
Jim
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Old 20 April 2010, 23:26   #2
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Country: UK - England
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Make: SR5.4
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Welcome to Ribnet

I wouldn't want 3" less freeboard on an SR4,or a powerhead 3" closer to the water. The beauty of them is that they'll stand far more than they should for a boat that size. Why detract from it?

Personally I'd sell the one you just bought and buy a longshaft.
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Old 20 April 2010, 23:53   #3
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Engine: Yamaha 90hp 2T
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Quote:
Originally Posted by Nos4r2 View Post
Welcome to Ribnet

I wouldn't want 3" less freeboard on an SR4,or a powerhead 3" closer to the water. The beauty of them is that they'll stand far more than they should for a boat that size. Why detract from it?

Personally I'd sell the one you just bought and buy a longshaft.
cheers for the quick reply.
apart from it being easier for water to get into the boat from over the transom im unsure what the disadvantages actually are. i assumed it wouldnt make a massive differenct to the boat overall and would have thought the lower centre of gravity might have helped with stability but i take it i see it wrong?
could you give a bit more detail as to what 3" less freeboard would cause and what the powerhead being closer aswell would cause problem wise?
cheers
Jim
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Old 21 April 2010, 01:33   #4
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Country: Other
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Boat name: Seawolf
Make: Osprey Vipermax 5.8
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Engine: Etec 150
Join Date: Mar 2006
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Water washing in over the transom and flooding the boat, and your air intake being a few inches closer to the water are two disadvantages that spring to mind.

Flooding is a particular problem going astern, my Destroyer used to fill up with any sort of speed astern and chopping a big lump out of the transom would have been the last thing I wanted to do on that, which was a fair bit bigger boat. You'd risk turning it into a submarine with a bit too much woof in reverse- and any sort of sea on the stern might be a bit wet on board too
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Old 21 April 2010, 12:54   #5
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Country: UK - Wales
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Make: Avon 5.4 Searider
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Engine: yamaha 80
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To be honest if my 5.4 is anything to go by, then you will find it wet enough without lowering the transom.
you will either need to get an extension, or find another engine .
With the transom lowered a few inches I think water will pour in when you are not under way. My 5.4 doesnt have much freeboard and thats with the flooding hull blocked off.
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Old 21 April 2010, 14:25   #6
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Country: UK - England
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Boat name: Dominator
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Engine: Yam 85
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Basically, what they said!
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Old 21 April 2010, 21:48   #7
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this is my old searider at rest. I wouldn't want 3 inches cut off the transom
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Old 21 April 2010, 23:07   #8
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Quote:
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this is my old searider at rest. I wouldn't want 3 inches cut off the transom
They always say the most effective bilge pump is a frightened man with a bucket
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