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Old 28 November 2011, 13:59   #111
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88.9km/hr apparently
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Old 01 December 2011, 04:34   #112
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5.6 avon adventure, 100hp 4 stroke- 40 knots on GPS.

achieved on a nice small chop and 2 up.

cheers
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Old 01 December 2011, 04:56   #113
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I had the exact same set up. Lovely combination, don't think I ever had it going that fast though but I expect my sons did!Click image for larger version

Name:	Rib.jpg
Views:	262
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ID:	64189 Nice one.
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Old 01 December 2011, 05:04   #114
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Quote:
Originally Posted by bkils@mac.com View Post
yup 48 knots (Kts) as in 55.2 Mph = 88.9 Km/h = 24.7 m/s.
You see that is why our two countries have a "special relationship"...

... because FIBnet exists on both sides of the pond

Its just about possible to get to 38 knots with that prop on the right engine:

13" rotating at 6500* / 1.8** rpm (x 60 min/hr) = 2816666 "/hr = 38.6 Nautical miles / hr.

* the maximum RPM for any 2-stroke I've ever seen.
** the minimum gearbox ratio of any outboard I've ever seen.

Even then a 10% prop slip is considered normal, and less than about 8% amazing (or unbelievable depending on your outlook!).

If you really are getting 48 knots the engine must be screaming its tits off (over 8000 rpm) in which case a video of it blowing up would be good.
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Old 01 December 2011, 05:19   #115
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I calculated 37 mph using the max RPM of 5500 from the yamaha site and the 1.86 ratio for the lower unit. I agree about the video!

Test was Wednesday so we should get the pictures today! Cant wait!
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Old 01 December 2011, 09:19   #116
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If you really are getting 48 knots the engine must be screaming its tits off (over 8000 rpm) in which case a video of it blowing up would be good.
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Old 01 December 2011, 09:32   #117
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For my friends on the other side of the pond, the mathmagicians and those by now out of popcorn: I took her on the Hudson River yesterday but there was some wind and chop and I wasn't able to duplicate the exact number I got on flat water. Anyways here's the raw video clip: Hudson River, New York on Vimeo
Enjoy the holidays :-) Over and Out.
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Old 01 December 2011, 09:57   #118
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I had the exact same set up. Lovely combination, don't think I ever had it going that fast though but I expect my sons did!Attachment 64189 Nice one.


my own one i've only seen the magic number twice of 40knots on the gps.

it is more normal to see 35/36 knots from it as i'm usually out with 3/4 people.

cheers
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Old 01 December 2011, 10:26   #119
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Fair fecks Bjoern I saw 44.5kts on that there screen sir!
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Old 01 December 2011, 10:28   #120
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Quote:
Originally Posted by bkils@mac.com View Post
For my friends on the other side of the pond, the mathmagicians and those by now out of popcorn: I took her on the Hudson River yesterday but there was some wind and chop and I wasn't able to duplicate the exact number I got on flat water. Anyways here's the raw video clip: Hudson River, New York on Vimeo
Enjoy the holidays :-) Over and Out.
That looks impressive - was that 44 point something?

Is your boat a Rescue spec / deluxe / or an early boat?
Engine a new Yam 50hp 2 stroke? We can't get those here unfortunately. What RPM were you making.?
Standard Al prop or SS?

Was there any current and did you run the other way as well?

I'd love a 48 knot searider. :-)
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