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Old 30 December 2010, 17:19   #1
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Repower a Humber Destroyer

I have a humber destroyer 5.8 with an old 150 mariner 2 stroke that's EOL - a friend of mine has a honda 90 4 stroke and thinking of trying it.

I know, I cannot expect the same power, but should a 90 4 stroke be enough to play around?

What about fuel consumption comparing HP to weight?
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Old 30 December 2010, 17:28   #2
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Imagine taking the engine out of an aging Lamborghini and replacing it with one from a Toyota Yaris. It'll move.
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Old 30 December 2010, 17:39   #3
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Dave Mallet aka wavlength has a 6m Destroyer with a 90hp four stroke, goes very well considering hp / kg , I would expect about 35 knots.

90hp four stroke will use about 1litre per nm

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Old 30 December 2010, 17:50   #4
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Curent destroyer (2009 model) with a 90 opti makes 38kts and averages about 0.8l/nm. Ok its a 2 stroke so id expect Jono's estimate to be pretty close to reality.
Hope it helps you.
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Old 31 December 2010, 03:11   #5
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Quote:
Originally Posted by Jono Garton View Post
Dave Mallet aka wavlength has a 6m Destroyer with a 90hp four stroke,
Funny that, 'coz Andy Scholes aka 'Sticky' has a 90 Honda on a 5.5 Gemini and that's as flat as a fart.

Describing 35knts tops for a 6m boat as 'goes very well', sounds like Jono is trying to flog it.
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Old 31 December 2010, 03:18   #6
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Quote:
Originally Posted by BarflyRIB View Post
I have a humber destroyer 5.8 with an old 150 mariner 2 stroke that's EOL - a friend of mine has a honda 90 4 stroke and thinking of trying it.

I know, I cannot expect the same power, but should a 90 4 stroke be enough to play around?

What about fuel consumption comparing HP to weight?
Wow thats quite a jump and will be equivalent to about half as much power on the rib.
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Old 31 December 2010, 03:53   #7
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Wow thats quite a jump and will be equivalent to about half as much power on the rib.
Half the fuel consumption as well though
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Old 31 December 2010, 04:06   #8
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Half the fuel consumption as well though
Probably not. The 90 would be getting it's @rse whipped all day to keep it near it's 35knts.

Imagine reselling it. Any prospective buyer is gonna think that the main engine has been pinched.
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Old 31 December 2010, 06:26   #9
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I have a humber destroyer 5.8 with an old 150 mariner 2 stroke that's EOL - a friend of mine has a honda 90 4 stroke and thinking of trying it.

I know, I cannot expect the same power, but should a 90 4 stroke be enough to play around?

What about fuel consumption comparing HP to weight?
There's a Honda 135hp here, but it's an extra-long-shaft? Seems expensive for the hours on it. http://www.findafishingboat.com/hond...-shaft/DS29943
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Old 01 January 2011, 11:43   #10
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I have a suzi 90 on a 5.8m, admittedly its a bit lardy with a dual console, aux, twin batteries and about 100l of fuel but I can cruise 2 up at around 24 knots and get 30 flat out.
Even without all the extra stuff I don't think 38 knots is realistic with a 4 stroker
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Old 01 January 2011, 14:18   #11
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I am getting about 30-34 knots on mine (just hitting about 4500 rpm) - 9o hp tohatso on 5.85m. Mike

BTW Happy New Year
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Old 01 January 2011, 14:30   #12
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I am getting about 30-34 knots on mine (just hitting about 4500 rpm) - 9o hp tohatso on 5.85m. Mike

BTW Happy New Year
Whats WOT?
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Old 01 January 2011, 14:43   #13
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Whats WOT?
WOT = Wide Open Throttle (its an acronym mate)
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Old 01 January 2011, 15:02   #14
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Whats WOT?
You know, WOT, one of the two positions on a RNLI throttle:

1. NOT
2. WOT

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Old 01 January 2011, 16:14   #15
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You know, WOT, one of the two positions on a RNLI throttle:

1. NOT
2. WOT

They wouldn't understand, they don't let Chewy or Dan at the Helm
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Old 01 January 2011, 16:25   #16
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They wouldn't understand, they don't let Chewy or Dan at the Helm
I have for you a Spoon, so you can Stir It some more...
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Old 01 January 2011, 16:32   #17
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WOT = Wide Open Throttle (its an acronym mate)
I know that soft arse, I was asking him as in "whats the rpm at WOT" as he mentioned 4500rpm.

Quote:
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They wouldn't understand, they don't let Chewy or Dan at the Helm
Times have changed since you were last here....
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Old 01 January 2011, 16:42   #18
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Whats WOT?
Hi Chewy,

That is WOT - the prop setup is keeping revs down to just over 4500, book says WOT should max out at 5500. Going to have a play with new props etc in feb. Just finished running in so haven't bothered so far..

Mike
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Old 01 January 2011, 16:50   #19
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Hi Chewy,

That is WOT - the prop setup is keeping revs down to just over 4500, book says WOT should max out at 5500. Going to have a play with new props etc in feb. Just finished running in so haven't bothered so far..

Mike
Glad someone knew what I was on about, should get a few more knots with it revving to 5500rpm.
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Old 02 January 2011, 03:47   #20
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Times have changed since you were last here....
and here too!!
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