Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 07-06-2012, 09:19   #1
Registered User

Join Date: Jun 2012
Posts: 2
Fuel burn for a 9.9hp Yamaha outboard

Anyone have an idea of what the hourly fuel burn is on a 9.9 hp Yamaha four stroke pushing a 4k lb sailboat ?
__________________

__________________
oneilseamark is offline   Reply With Quote
Old 07-06-2012, 09:48   #2
Registered User
 
bruce smith's Avatar

Join Date: Jul 2008
Location: puget sound/ caribbean
Boat: never wrecked a boat while awake or sober
Posts: 330
Re: Fuel burn for a 9.9hp Yamaha outboard

For 2 cycles, the rate is roughly one gal per hour per ten hp., wot.
I would guess that you would not be running wide open throttle with a 4 cycle , and of course they use less fuel.
The vessel itself has very little to do with fuel use. It would use about the same, per hour, on a planing skiff going 20 or a barge going 2.
So, I think you will easily get 2 hpg,maybe a tad more, at about half throttle
__________________

__________________
bruce smith is offline   Reply With Quote
Old 07-06-2012, 16:26   #3
Registered User

Join Date: Apr 2011
Location: Cooktown,Australia.(only to collect my mail)
Boat: Fastback 32 cat.
Posts: 158
Re: Fuel burn for a 9.9hp Yamaha outboard

I average 1.3 liters per hour @ 3000 to 3500 rpm doing 5 to 5.5 knots in no wind, consumption goes to about 3.5 liters/hour WOT doing 6.7 knots. I changed to a 7 inch pitch prop from 9.25 inch ,no change in fuel consumption but gained .3 of a knot at WOT. I assume you have a high thrust motor ?
__________________
Ian R is offline   Reply With Quote
Old 07-06-2012, 16:46   #4
Registered User

Join Date: Jun 2012
Posts: 2
I assume it's high thrust. It's new to the owner. Thanks for the great info!!
__________________
oneilseamark is offline   Reply With Quote
Old 10-06-2012, 05:19   #5
Registered User

Join Date: May 2012
Boat: Perry 43 Catamaran
Posts: 17
Re: Fuel burn for a 9.9hp Yamaha outboard

On my old catamaran I ran 2 of these motors and consumed approx 5.5 litres per hour on both motors at full throttle. I had the high thrust props. Obviously significantly less when run at less revs.
__________________
HueyHuey is offline   Reply With Quote
Old 29-06-2012, 05:31   #6
Registered User

Join Date: Apr 2011
Location: Cooktown,Australia.(only to collect my mail)
Boat: Fastback 32 cat.
Posts: 158
Re: Fuel burn for a 9.9hp Yamaha outboard

The yamaha service manual quotes maximum fuel consumption of 3.9 liters/hour @ 6000 rpm for the 212 cc motors.
__________________
Ian R is offline   Reply With Quote
Old 29-06-2012, 05:54   #7
Registered User
 
cjones's Avatar

Join Date: Sep 2011
Location: Denver, CO
Boat: O'Day 27
Posts: 9
Images: 3
Re: Fuel burn for a 9.9hp Yamaha outboard

Seems like numbers are consistent. I have one on a 27' Oday and running at about half throttle results in a burn rate of .5 gallons per hour. Wish I had a better way to track RPM but have no tachometer.
__________________
cjones is offline   Reply With Quote
Old 29-06-2012, 06:53   #8
Registered User
 
neilpride's Avatar

Join Date: Jul 2009
Location: in the world
Boat: csy 44 tall rig.
Posts: 3,099
Re: Fuel burn for a 9.9hp Yamaha outboard

I own a 9.9 4 stroke for 4 years before i get the engine stoled in St Lucia , i can give you 2 good advices based in this engine, 1. Try to fresh water flush this engine often if you can , 2. Use the Factory aproved or a equivalent oil and change it at the regular intervals.

Flushing the engine save you lots of cronic water flow problems and expensive repair bills , mine get some internal corrosion at the oil pan case and the water flow is restricted giving us a terrible nightmare to found the problem.

In other words is a great engine , and can last forever if you take care of this 2 points.

No idea about the fuel burn, but i remember the gas at the tank last for a long while,
my actual 15 enduro 2 stroke suck the whole tank in 2 days !!
Cheers.
__________________
neilpride is offline   Reply With Quote
Old 29-06-2012, 07:28   #9
Marine Service Provider
 
Factor's Avatar

Join Date: Dec 2006
Location: Brisbane Australia
Boat: Corsair Dash MKII
Posts: 4,086
Re: Fuel burn for a 9.9hp Yamaha outboard

Got two, life time average so far is about 1.15 ltres per hour per motor. Can use up to 2.2 litres per hour if pushing hard.
__________________

__________________
Factor is online now   Reply With Quote
Reply

Tags
fuel

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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 -7. The time now is 07:10.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.