Outboard fuel comsumption

[Guest]

Hi,

Can anyone advise me if there is a rough calculator for gph used by outboard engines of around 40hp, i know there are many factors involved in this, but a rough guide for small planing hulls at various throttle settings would be great!

Cheers

 

[boatmad2]

Very roughly for 2 strokes its 1 gallon per hour for every ten horse power used ie
a ten horse flat out is 1 gallon/hour
a 50 " " " 5 gallon/hour
note that closing the throttle a bit makes quite a reduction in consumption, my 9hp at about mid throttle cruiseing speed burns about half a gallon per hour. Note that if you try to run to slow you get a miss fire called 4 stroking and the plugs will oil up.
Hope this helps if not to scary

 

[DavidP]

This is probably not what you want ,but my friend has an 18ft teal with a 60hp yamaha about 2 years old .
to travel from calshot , southampton to christchurch ledge and back ,at between 20/30 mph we burn about 8/10 gals

David.