Fuel burn....

Alanpatt · 16 June 2013, 10:50

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.

Nos4r2 · 16 June 2013, 11:29

Depends how long you want to be running for but I usually carry 3x22.5 litre tanks as a minimum on mine.

Maximus · 16 June 2013, 11:32

Quote:

Originally Posted by Alanpatt

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!!!

Nos4r2 · 16 June 2013, 11:35

Quote:

Originally Posted by Maximus

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.

Alanpatt · 16 June 2013, 14:23

Brilliant, cheers lads.

Bushrider · 16 June 2013, 14:53

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

Boats&Outboards · 16 June 2013, 15:25

Try this as a guide

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

www.BoatsandOutboards4Sale.co.uk

wiLlfish · 16 June 2013, 15:27

Quote:

Originally Posted by Bushrider

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

Bushrider · 16 June 2013, 16:07

Quote:

Originally Posted by wiLlfish

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

ian parkes · 16 June 2013, 16:18

Quote:

Originally Posted by Nos4r2

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

Locozodiac · 16 June 2013, 16:34

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.

Happy Boating

Maximus · 16 June 2013, 16:37

Quote:

Originally Posted by ian parkes

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!!

Nos4r2 · 16 June 2013, 16:49

Quote:

Originally Posted by ian parkes

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...

Alanpatt · 16 June 2013, 16:55

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!!

Bushrider · 16 June 2013, 16:59

for my SR = 3500-4000rpm

ian parkes · 16 June 2013, 17:07

Quote:

Originally Posted by Nos4r2

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

Mollers · 16 June 2013, 18:50

Quote:

Originally Posted by ian parkes

my daughter and her boyfriend have a 5.3 chinook

Caja?! She's about 10!

richardjawilson · 16 June 2013, 18:50

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

ian parkes · 16 June 2013, 21:11

Quote:

Originally Posted by Mollers

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

Mollers · 16 June 2013, 21:13

Quote:

Originally Posted by ian parkes

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.