Reply
 
Thread Tools Search this Thread
 
Old 29 September 2011, 02:52   #1
Member
 
Country: UK - England
Town: fareham
Boat name: shalwi
Make: ribeye 600
Length: 6m +
Engine: 115 yamaha
Join Date: Sep 2011
Posts: 8
Send a message via AIM to andy jeffrey
fuel consumption

Hi is there anyone out there who can advise me on the rough distance/time i should get from a yamaha 115 4 stroke on a ribeye 600 as cruising speed ie 20/25 knots , tank holds 90lts , the fuel gauge is all over the place when at sea ??????
__________________

__________________
andy jeffrey is offline   Reply With Quote
Old 29 September 2011, 03:33   #2
RIBnet admin team
 
Poly's Avatar
 
Country: UK - Scotland
Boat name: imposter
Make: FunYak
Length: 3m +
Engine: 2 stroke YAM 20 HP
MMSI: 235089819
Join Date: Sep 2005
Posts: 10,114
Search the forum you will find loads on fuel consumption. However at cruising speeds almost all ribs run at roughly 1 L/NM (+/- 20%). DO NOT rely on this as your minimum amount of fuel for a journey though.
__________________
Poly is offline   Reply With Quote
Old 29 September 2011, 07:43   #3
Member
 
Country: UK - England
Town: NW& wherever the boat is!
Boat name: depends on m'mood!
Make: Humbers/15-24m cats
Length: 6m +
Engine: etec130/big volvos
MMSI: many and various
Join Date: Nov 2001
Posts: 1,815
no such thing as mpg at sea of course. We usually work on1l /mile in reasonable conditions as a pessimistic figure, but that could go up considerably if the weather turns against you. Is it an underfloor tank or an above deck thing?
__________________
Dave M
www.wavelengthtraining.co.uk
wavelength is offline   Reply With Quote
Old 29 September 2011, 09:22   #4
Member
 
Country: UK - England
Town: fareham
Boat name: shalwi
Make: ribeye 600
Length: 6m +
Engine: 115 yamaha
Join Date: Sep 2011
Posts: 8
Send a message via AIM to andy jeffrey
hi its an under floor tank
__________________
andy jeffrey is offline   Reply With Quote
Old 29 September 2011, 10:44   #5
Member
 
Country: UK - England
Town: NW& wherever the boat is!
Boat name: depends on m'mood!
Make: Humbers/15-24m cats
Length: 6m +
Engine: etec130/big volvos
MMSI: many and various
Join Date: Nov 2001
Posts: 1,815
problem is you can't dip it then. Thats one of the various reasons we try and keep clear of u/floor tanks whenever we can. The big boat I am sat on at the monment has the sight tubes checked every day cos I wont trust just guages if I have any choice in the matter. We get on a few of the smaller boats in the fleet to deliver them occasionally and they are just on lcd readouts for the fuel tanks-not good for the nerves when you step onto a strange boat and set off relying on them and the good log keeping of the previous skipper.
Lot of good discussion on here in the past year or two re fuel sensors and flowmeters. Need to have a look around or some of the lads will be able to put you right.
__________________
Dave M
www.wavelengthtraining.co.uk
wavelength is offline   Reply With Quote
Old 29 September 2011, 12:09   #6
Member
 
Country: UK - Scotland
Boat name: Wildheart
Make: Humber/Delta Seasafe
Length: 5m +
Engine: Merc 60 Clamshell
MMSI: 235068449
Join Date: Apr 2007
Posts: 4,611
if you have time best bet is fill to the cap (or a known point o nthe filler line) go for a burn (not too far!) and use your GPS to record average speed / distance etc. (can use a cheap handheld if you don't have a fancy plotter) Then when you get back, top it up to the same place, & take a note of how much went in.

Only after a few trips like that will you get a feel for how much it actually guzzles. That won't take tide into account numerically, but unless you are really unlucky you should get a rolling avearage of with & against you.

I'm about to start that game with mine, as I only stopped burning 25:1 last trip out and have no idea how much it will now drink after the rebuild on "design mix". For what it's worth, on the 25:1 mix I was getting 1.1L/Nautical Mile, but that did include 3 hrs at displacement speed.
__________________
9D280 is offline   Reply With Quote
Old 29 September 2011, 16:29   #7
Member
 
Country: Other
Town: Rosas
Boat name: Conqueror
Make: Valiant
Length: 7m +
Engine: Outboard 150hp Merc
Join Date: Dec 2010
Posts: 541
Send a message via Skype™ to Courageous
9D has it right. I'm still in the dark with mine and carry 25L in a jerry can "just in case".
__________________
Courageous is offline   Reply With Quote
Old 29 September 2011, 18:05   #8
dnv
Member
 
Country: Germany
Town: Hamburg
Boat name: Der Delphin
Make: Parker
Length: 6m +
Engine: Inboard Diesel 120HP
Join Date: Dec 2008
Posts: 168
I prefer to calculate consumption in'liter per hour' at a certain rev, rather than per nm. Reason is tide:
If you run at 30kn, 5kn head or tail tide make a difference of 33% in speed over ground, in time, in liter per nm and consequently in consumption for same distance (35kn vs 25kn over ground at same revs).

Jan

Sent from my iPhone using Rib.net
__________________
dnv is offline   Reply With Quote
Old 30 September 2011, 00:21   #9
Member
 
Leapy's Avatar
 
Country: UK - England
Town: Sheepy Parva
Boat name: Sadly Sold
Length: no boat
Join Date: Sep 2008
Posts: 1,728
Quote:
Originally Posted by 9D280
if you have time best bet is fill to the cap (or a known point o nthe filler line) go for a burn (not too far!) and use your GPS to record average speed / distance etc. (can use a cheap handheld if you don't have a fancy plotter) Then when you get back, top it up to the same place, & take a note of how much went in.

Only after a few trips like that will you get a feel for how much it actually guzzles. That won't take tide into account numerically, but unless you are really unlucky you should get a rolling avearage of with & against you.
...and if you do that for a season (say) all the effects of wind, tide and everything else are averaged out. I've kept a simple fuel added/GPS distance travelled log for over 1000 miles now: 8.6mpg plus/minus naff all (can't be arsed with nm, litres or fathoms)...just add in your favourite safety margin for any trip you make
__________________
Leapy is offline   Reply With Quote
Old 30 September 2011, 05:11   #10
Member
 
Country: UK - Scotland
Boat name: Wildheart
Make: Humber/Delta Seasafe
Length: 5m +
Engine: Merc 60 Clamshell
MMSI: 235068449
Join Date: Apr 2007
Posts: 4,611
Quote:
Originally Posted by dnv View Post
I prefer to calculate consumption in'liter per hour' at a certain rev, rather than per nm. Reason is tide:
At risk of sounding like a trainspotter, I also calculate that! Thing is L/mile makes trip planning a lot easier!

Over a season, as said by leapy you get a warmer feeling that your guess is going to be accurate!
__________________

__________________
9D280 is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 07:14.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.