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Old 16 June 2013, 05:50   #1
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Fuel burn....

Hi all, without being out on my rib yet, I'm into the realms of 'how much fuel do i need'? It's a 5.4 searider with a mariner 90 2stroke. I'm not looking for exact numbers but a estimation would be good. Although its got 2 20ltr tanks, I don't fancy filling 2 Gerry cans just for the sake of it....

Cheers,

Al.
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Old 16 June 2013, 06:29   #2
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Depends how long you want to be running for but I usually carry 3x22.5 litre tanks as a minimum on mine.
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Old 16 June 2013, 06:32   #3
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Originally Posted by Alanpatt View Post
Hi all, without being out on my rib yet, I'm into the realms of 'how much fuel do i need'? It's a 5.4 searider with a mariner 90 2stroke. I'm not looking for exact numbers but a estimation would be good. Although its got 2 20ltr tanks, I don't fancy filling 2 Gerry cans just for the sake of it....

Cheers,

Al.
A litre a Mile + Safety Margin of at least 30% should see you OK if you're not Revving the Guts out of it...Matt h got the Fuel consumption considerbly higher if I re-call but there can't be another Like him about Surely!!!
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Old 16 June 2013, 06:35   #4
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A litre a Mile + Safety Margin of at least 30% should see you OK if you're not Revving the Guts out of it...Matt h got the Fuel consumption considerbly higher if I re-call but there can't be another Like him about Surely!!!
I've managed to get mine higher than 1m/L on a flat calm day a few times.

That 3rd tank is my safety margin.
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Old 16 June 2013, 09:23   #5
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Brilliant, cheers lads.
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Old 16 June 2013, 09:53   #6
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With a SR 5.4 & a Yammi 90hp 2 stroke I had a consumption of 0.5 Liter / km . Guess with your Motor will be similar
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Old 16 June 2013, 10:25   #7
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Try this as a guide

http://www.boat-fuel-economy.com/mer...ion-us-gallons

www.BoatsandOutboards4Sale.co.uk
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Old 16 June 2013, 10:27   #8
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I had a consumption of 0.5 Liter / km . Guess with your Motor will be similar
Noe itt wown't

Inn ingerland wee av myles nott kilometirs soe wen wee gow enywher wee av firther too gow
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Old 16 June 2013, 11:07   #9
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Noe itt wown't

Inn ingerland wee av myles nott kilometirs soe wen wee gow enywher wee av firther too gow
Ok - got it
5.64963mpg
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Old 16 June 2013, 11:18   #10
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I've managed to get mine higher than 1m/L on a flat calm day a few times.

That 3rd tank is my safety margin.
A few times you mean not that often .

be honest to the poor fellow now , he has to find out soon hopw much a 90 2 stroke really uses especially of you are havin some fun . He won't always have flat calm and following wind and tide .
I say fill those cans and allow for 1.5l a mile
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Old 16 June 2013, 11:34   #11
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A 2 strokes engine consumes 12% gallons of it's rated HP at wot. Used to be stated at 10%, but that's a very conservative %, better have more fuel remains calculating at 12% than none at 10%. A good fuel economy would be running 4000-4500 rpm at wot on flat, no wind water conditions.

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Old 16 June 2013, 11:37   #12
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A few times you mean not that often .

be honest to the poor fellow now , he has to find out soon hopw much a 90 2 stroke really uses especially of you are havin some fun . He won't always have flat calm and following wind and tide .
I say fill those cans and allow for 1.5l a mile
... SHITE! Matt h is'nt the Only one then!...Just goes to show how much Outboards have progressed...my Suzuki 250 even in Rough or Raceing has'nt got near 1.5 litres a Mile!!
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Old 16 June 2013, 11:49   #13
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A few times you mean not that often .

be honest to the poor fellow now , he has to find out soon hopw much a 90 2 stroke really uses especially of you are havin some fun . He won't always have flat calm and following wind and tide .
I say fill those cans and allow for 1.5l a mile
That run we took to the Eddystone,I worked out it was doing about less than 1 mile/litre in the flat calm when we were running at WOT, and it's propped just right.

If I cane it in the rough it uses more.

If I slow up , it does more than a mile per litre.

If you take 3 tanks, plan on only using 2...
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Old 16 June 2013, 11:55   #14
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Ok, that gives me a rough idea... So.....next question...what sort of rpm range do we use for cruising? I'm not even gonna ask what rpm I shouldn't exceed!?! RAMMING SPEED!!
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Old 16 June 2013, 11:59   #15
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for my SR = 3500-4000rpm
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Old 16 June 2013, 12:07   #16
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That run we took to the Eddystone,I worked out it was doing about less than 1 mile/litre in the flat calm when we were running at WOT, and it's propped just right.

If I cane it in the rough it uses more.

If I slow up , it does more than a mile per litre.

If you take 3 tanks, plan on only using 2...
I remember that day , it was a typical cruise on a calm day we all set off steady and slowly the throttles get pushed a bit more until I at least was flat out .
same thing happened last summer my daughter and her boyfriend have a 5.3 chinook with a lovely old yam 85 we cruised for about 6o miles and slowly steady turns to faster then you hit some cop etc and have some fun They used well over 1 litre a mile come the end of the day at least 1.5 When i had a go in that old chinook i could tell why , it just feels so understresed , even at wot its just doesn't feel like its working at all
I reckon the differerence with old carbed 2 strokes between going steady and driving them hard is almost double the fuel

Agree with bushrider there keep it below 4k and its good , my tohatsu 50 is really good on fuel cruising under 4 k and thats really just a smaller version of the same engine , ie 3 cyl 3 carbs
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Old 16 June 2013, 13:50   #17
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my daughter and her boyfriend have a 5.3 chinook
Caja?! She's about 10!
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Old 16 June 2013, 13:50   #18
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Sorry for thread drift, but for your info, below is a table for current fuel consumption of my Capelli 32 WA (hard boat) 10m with 2x250 Yamaha's. Fuel burn about 50-55 lph @ 23-25 kn popping up to a cheeky 190 lph @ 44 kn (havent spent too much time at that speed!)



Hours Used LPH Journey
09/12/2012 1.00 35.00 35.00 Torquay-Dmouth
10/12/2012 1.00 35.00 35.00 Dmouth-Hallsands
11/12/2012 1.00 10.00 10.00 Dmouth-Bness
20/04/2013 4.70 80.50 17.13 Dmouth-Start Point
21/04/2013 2.70 61.30 22.70 Dmouth-Torbay
28/04/2013 3.00 19.80 6.60 Bness-Dmouth
29/04/2013 3.50 176.20 50.34 Dmouth-Guernsey
30/04/2013 2.20 78.80 35.82 Guernsey-Jersey
01/05/2013 1.90 77.20 40.63 Jersey-Guernsey
01/05/2013 4.00 189.80 47.45 Guernsey-Dmouth
02/05/2013 0.80 7.20 9.00 Dmouth-Bness
31/05/2013 3.00 41.00 13.67 Bness-Scabbacombe-Dmouth
01/06/2013 2.10 44.40 21.14 Dmouth-Salcombe
02/06/2013 3.80 90.40 23.79 Salcombe-Thurlstone-Dmouth
03/06/2013 0.50 6.00 12.00 Dmouth-Bness
35.20 952.60 27.06
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Old 16 June 2013, 16:11   #19
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Caja?! She's about 10!
caja is 13 now mate , I have 2 older daughters in their mid 20's . makes me feel old, been a grandad for 3 years now
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Old 16 June 2013, 16:13   #20
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caja is 13 now mate , I have 2 older daughters in their mid 20's . makes me feel old, been a grandad for 3 years now
Blimey. Our youngest Megs, is now 17 and driving.
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