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Old 30 July 2010, 12:45   #1
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Dont want to start full debate

Dont want to start full debate again twin 90s or single 225 , twins giving about 40 knots single 46knots but then will have to look at a aux i really can not make my mind up on this
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Old 30 July 2010, 12:52   #2
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i would think the speed difference would be more than that.
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Old 30 July 2010, 12:56   #3
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You lose about 30% power I think running twins.
I have a single outboard on my RIB but will be fitting twin outboards to the Tremlett.
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Old 30 July 2010, 12:58   #4
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i would think the speed difference would be more than that.

thanks the figures are from ribcraft
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Old 30 July 2010, 13:53   #5
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thanks the figures are from ribcraft
Its not just the speed its the cost of fuel. If you are going with twins then you will also need twin tanks, twin electrical systems to actually have the full benefit.

IMHO a well serviced and looked after single engine and a decent sized aux is a better bet, unless the boat is going to be doing commercial or lots of offshire work where you need the added security.

Where are you going to be using the boat and what sort of use do you plan.
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Old 30 July 2010, 16:06   #6
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Single for me too

Apart from the VERY good points Chris makes, the extra weight,and corresponding handling,AND loss of performance on a MID SIZE RIB [not to mention the considerable extra exspence] coupled with the loss of economy twins represent... would sway me to a GOOD Large Single every time!They are pretty reliable these days!!
Also, and it may be the last thing your thinking about at the moment!! but I think the used market would more often than not, favour a good performing,well balanced, single set up!
Either way I wish you all the best with the new boat!
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Old 30 July 2010, 17:11   #7
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Also, and it may be the last thing your thinking about at the moment!! but I think the used market would more often than not, favour a good performing,well balanced, single set up!
I'm not so sure. I keep an eye on this, and they seem to sell well, some of them very well. Obviously the market is limited, but then so is the product, so much of a muchness. They certainly seem to command a small premium over a similar "single". I wouldn't let that aspect influence a purchase.
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Old 30 July 2010, 17:34   #8
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One aspect of having twins that people tend not to think about is reliability.

Yes, if one breaks down when you're out the other will get you home.

But having twins means you WILL have twice as many breakdowns and obviously you're not going to take the boat out anywhere if they're not both running right. Result= boat spends twice as long sat on the trailer waiting for outboard tech, parts etc.
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Old 30 July 2010, 18:51   #9
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But having twins means you WILL have twice as many breakdowns and obviously you're not going to take the boat out anywhere if they're not both running right. Result= boat spends twice as long sat on the trailer waiting for outboard tech, parts etc.
So what you are saying is that they are better for getting home but sh&t for getting out there in the first place

Never thought about it like that, but good point
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Old 31 July 2010, 03:39   #10
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thanks the figures are from ribcraft
The twin rig has 45hp less than the 225 single but only goes 6 knots slower? I would ask them if this is from actual experience or calculations personally
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