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Old 10 December 2011, 11:09   #21
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Hi

re your points

1: this is 100% wrong. they can sell 2 strokes and other manufactures do
2: you have no evidence for this so why you have yoiu have writen it I have no idea
4: It does not matter what you measure in. The percentage difference is still the same.

FACT 1+ 1=2 and old 2 strokes burn a lot more fuel than new 4 strokes

Chris

Please dont take our word for why dont you join us on the following wager that if 9D280 loses he will give 6K to clyde outboards, 1K to us to reprove this point yet again! and the other 5K will be given to RNLI. If we lose we give him a free 60hp Honda engine with an RRP of over 8k

We put 9D280' engine on the back of a shetland 570 and a new honda on our other pals shetland 570. both are at balloch so easy to do. we the set them up to cruise at anywhere between 22-26 mph with 20l of fuel each traveling side by side.

a simple easy test and the boats will even be the same!

There is huge upside for doing this

chris gets to see a new honda
RNLI get a good donation
It will answer the question
It will be great fun

The good thing about this test is the faster we go the more fuel the Honda will burn, but so will the old 2 stroke and as a percentage difference this will stay the same or widen further.

so 9D280 are you ready for some fun and to give money to RNLI?


Dave
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Old 12 December 2011, 08:00   #22
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Quote:
Originally Posted by clydeoutboards View Post
Hi

re your points

1: this is 100% wrong. they can sell 2 strokes and other manufactures do
2: you have no evidence for this so why you have yoiu have writen it I have no idea
4: It does not matter what you measure in. The percentage difference is still the same.
to your replies

1) Not as far as Chris is concerned, unless he is running some commercial outfit or is actually in Oz and pretending to live in Scotland?

2) and I requote:
"Results will vary depending upon operating conditions (boat design, size, weight (load), weather, etc.)"
So can you tell me exactly how they got those numbers with a disclaimer like that?

4) so you are telling me if you strap a 4 stroke 60 which is on paper 50% more efficient on the back of my rib a couple of weeks ago I could have done the entire length of Loch Lomond & back on 15.2L of fuel? That ulitmately what you are claiming.

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Originally Posted by clydeoutboards View Post

FACT 1+ 1=2 and old 2 strokes burn a lot more fuel than new 4 strokes
As I have said millions of times before - at idle / low rpm pottering about rescue / fishing - yes I totally agree. But at WOT you still need to generate 60Hp via a machine that has a fair few laws of thermodynamics, mechanical inefficiency (at the heart of the machine it's reciprocating) and burning of fuel in an enclosed space at play.

or: Define "lot"? (see below)


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Originally Posted by clydeoutboards View Post
Chris

Please dont take our word for why dont you join us on the following wager that if 9D280 loses he will give 6K to clyde outboards, 1K to us to reprove this point yet again! and the other 5K will be given to RNLI. If we lose we give him a free 60hp Honda engine with an RRP of over 8k

We put 9D280' engine on the back of a shetland 570 and a new honda on our other pals shetland 570. both are at balloch so easy to do. we the set them up to cruise at anywhere between 22-26 mph with 20l of fuel each traveling side by side.

a simple easy test and the boats will even be the same!

There is huge upside for doing this

chris gets to see a new honda
RNLI get a good donation
It will answer the question
It will be great fun

The good thing about this test is the faster we go the more fuel the Honda will burn, but so will the old 2 stroke and as a percentage difference this will stay the same or widen further.
errrr look at your own graphs. The faster you go the better for the 2-stroke!

Quote:
Originally Posted by clydeoutboards View Post
so 9D280 are you ready for some fun and to give money to RNLI?

Dave
As I've said already, I know it's going to be a bit more efficient, but had you actually bothered to read my original comment, you would note the use of the words "WOT" and "naff all" in the same sentence. I am fully aware there will be a difference but a small one (see below).

As I have never said 2- strokes were more efficient but only that the difference at WOT isn't as big as some may imply, I'm going to politely decline your wager. The RNLI gets plenty of donations from me already so they aren't going to loose out




Let's do some maths relevant to Chris' situation:
(Chis, feel free to substitute your actual mileage & engine / fuel costs to the equation for a real world appraisal)


Chris could buy 8Ks worth of wonder engine, which will burn "50% less fuel" than whatever second 2- stroke hand lump he buys. So let's assume this 50% is actually acheivable in the real world, and imagine Chris could also buy a really good condition 2- stroke for, say 2000. Going in point: 6k still in his pocket. Call it 4800L at 1.25/ L

Now, lets say Chris is out every weekend doing an avearage of 50 nautical miles per weekend over the year. If he were using my rib with it's 1960s designed engine that would equate to 50*0.82L= 41L / weekend. or 2132L per year.

So, let's now imagine he's got the wonder engine that literally drinks half of what my old 2- stroke does. (I use this to make a point - I am fully aware nobody is claiming real world numbers like this) so Chris' boat would then drink 1066L/year.

So, to save 1066L/year (1332.50) He'd be spending 6k. Or put another way a 4.5 years to break even. And that with a fairly hefty use for a leisure boat. If he's only out every other weekend that's a 9 year payback!

Now, doing the same maths with a 30% save, it's an annual 852.8L / saving or 1066 and a 5.5 year breakeven for an every weekend assumption.


Those numbers are still screaming 2- stroke to me....
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Old 12 December 2011, 12:55   #23
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Quote:
Originally Posted by 9D280 View Post
Chris could buy 8Ks worth of wonder engine, which will burn "50% less fuel" than whatever second 2-stroke hand lump he buys. So let's assume this 50% is actually achievable in the real world, and imagine Chris could also buy a really good condition 2- stroke for, say 2000. Going in point: 6k still in his pocket. Call it 4800L at 1.25/L. Those numbers are still screaming 2-stroke to me....
I think we need to get Carol in for this one!

+1 for 9D280
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Old 12 December 2011, 14:27   #24
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I see both sides

Yes over 5 years to "break even" but that's all the while running with a almost silent, smoke free reliable engine under warranty. After the 5 years it's resale would be say 3,000 so that's also bringing the numbers down. The 2 stroke in that same 5 years may have run it's life meaning 1 of 2 things. Either no re-sale value or you have to spend another 2,000 to replace. Also as its already 2nd hand when you buy it there's no guarantees it will run for the 5 years without faults, more cost. Worst case it blows a piston or two and again your in for another 2,000 to replace the engine. You could end up doing that twice in the 5 years (extreme and unlikely) so you've run with an old 2 stroke at the same cost as you could with a fancy new 4 stroke

On the other hand like you say most leisure use is very limited so it's a high outlay for something that you may not use too much. Plus it's more expensive to service, more risk for theft.

Peter ~ Boatsandoutboards4sale ~ askboatsandoutboards4sale@sky.com ~ 07930 421007
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Old 13 December 2011, 09:48   #25
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Why do you want so much power on a dr 490?

I have a etec 60 on mine and it is plenty. I cannot use it at wot as the boat becomes unstable as it approaches 30 KN. The extra weight on the transom will also distroy the handling of a DR 490. The etec is 112 kgs and I still have to ballist the bow. My advice use a 60 hp of a weight no greater than 112 kgs. lighter is better.

TSM
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Old 13 December 2011, 10:34   #26
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Why do you want so much power on a dr 490?

I have a etec 60 on mine and it is plenty. I cannot use it at wot as the boat becomes unstable as it approaches 30 KN. The extra weight on the transom will also distroy the handling of a DR 490. The etec is 112 kgs and I still have to ballist the bow. My advice use a 60 hp of a weight no greater than 112 kgs. lighter is better.

TSM
Thanks for the advice what size of prop do you have on your etec?

Cheers
Chris
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Old 13 December 2011, 11:41   #27
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For diving and heavy loads 13.25 dai by 17 pitch

say engine 112 kg
fuel 60 kg
ballist in anchor locker 35kg
A frame and assorted items 30 kg
battery 10 kg
anchor and chain 12 KG
DIVERS AND COXN 570 KG
total 829 kgs.

The boat feels wallowy with this load but the etec 60 and a 13 * 17 prop will move it no problem (on the plane)
for ligher runs i use a 13 *19 prop

fuel usage varies from 1.3nm/l to 1.5 nm/l

TSM
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Old 13 December 2011, 13:20   #28
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Maybe the practical implementation in most cases is not so important but it is totally correct as 9D280 says, there is basically no difference in consumption between old 2 stroke and modern engines.

Have noted this in many tests in the 90 hp range, just searched randomly one:
http://marine.honda.com/pdf/props/St...20-%20BF90.pdf

Here the honda uses aprox 36 l/h. Think would beat that one with my old YAM AETO 90
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Old 13 December 2011, 13:37   #29
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interesting ( if old ) comparison of 115hp's here .
Comparison Test: Five Outboard Motors - Popular Mechanics

I agree that the savings in consumption do not add up for leisure use but IMO a quieter and newer unit make for more enjoyable boating and a much easier sale if required, plus the reduced consumption means less can carrying which i struggle with.
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Old 13 December 2011, 14:02   #30
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If your hull was built before 2- stroke was banned...
Quote:
Originally Posted by 9D280 View Post
It's a manufacturer's leaflet. They can't sell 2-stroke any more. It's in their interests to big up 4-st.
This comment may confuse some readers. I guess you refer to "old school" non injection 2-strokes, but others may not realise this.

Obviously, manufacturers still produce and sell 2 stroke direct injection engines. Again, it's the emissions that are banned, not the technology...
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