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Old 01 November 2009, 22:13   #1
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Country: UK - N Ireland
Town: Portrush
Boat name: G'Noah
Make: Redbay
Length: 6m +
Engine: outboard petrol 225
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Auxillary Engine Recommendation

What SMALL auxillary engine would anyone recommend for a Redbay 6.5 wraparound?

Main engine is an Evinrude 225.

Changing for twin 150 is not a considered option hence the SMALL in the question.

I have also a yacht so coming home at 5 to 6 knots is a normal experience :-)
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Old 01 November 2009, 22:17   #2
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9.9 or 10 hp would be nice and run at half throttle at 5/6 knots with ease. However far more important is getting the prop down in clean water below the tansom. If the flow of water to the aux prop is blocked by the transom you are going nowhere fast.

Pete
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Old 01 November 2009, 22:37   #3
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Quote:
Originally Posted by Pete7 View Post
9.9 or 10 hp would be nice and run at half throttle at 5/6 knots with ease. However far more important is getting the prop down in clean water below the tansom. If the flow of water to the aux prop is blocked by the transom you are going nowhere fast.

Pete
Thanks Pete7,
I was considering putting one of the spring loaded ob brackets on but I guess that size of engine would require to be kept on board as I fear it would unbalance the rib a bit like the two domestic batteries give my Westerly Storm a slight list to starboard.

Is this the case?
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Old 02 November 2009, 09:28   #4
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Just a thought on the transom being in the way..... Until recently my aux was a short shaft, but as my transom isn't vertical, I sat it on the "full up" pin, and ended up with nearly a foot between the prop & the transom immediately ahead of it. As it was never going to plane, the water filled the "hole" behind the boat faster than the wee thing could propel it out.

The main reason I swapped for a longshaft was that it now means the prop doesn't get plucked out the water at every other wave!
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Old 02 November 2009, 09:28   #5
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Probably the ultimate power to weight aux is the Tohatsu 9.8hp 2-stroke. I have one for those attributes as a main engine on my small Zodiac.

At around 26kg it weighs a fraction less than a 4hp Mariner 4-stroke. A no-nonsense design with no techy stuff to go wrong and a good name for reliability. Easy to start and quiet for a 2-stroke. Ideally the standard prop will need changing to push a heavier boat at displacement speeds.



I have one of those sprung aux brackets on my grp boat and even with a 3.5hp it takes a fair bit of stick when nipping along in the bumpy stuff. If there was any possibility of a strong fixed bracket or transom mount I'd go for it.

Have a look at this thread too on failing aux brackets...

http://rib.net/forum/showthread.php?t=30592

David
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Old 02 November 2009, 10:14   #6
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Fenlander has got it "spot on". The Tohatsu 9.8hp is a fantastic engine and weighs so much less than all the others. My choice every time. Even a small weight reduction makes handling an engine so much easier, especially when the Rib is bouncing up and down in a swell. Also the O/B bracket can be less robust to support the lighter engine.
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Old 02 November 2009, 13:59   #7
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As regards listing, I don't think this will be an issue in the 6.5, no matter where you mount or stow the aux.

I occasionally have a DonegalDan (= about 4 toohotsues) perched on our port tube and the only list I've noticed is his list of luncheon requests
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