fuel burn ?

gsouthern

Cadet
Joined
Dec 11, 2011
Messages
7
Hi, newbie here, I have a ,91 20hp Johnson electric start on a 11' Boston Whaler, and am curious as to what the fuel burn is on this engine.
The reason I ask is first because it has a new (installed by previous owner) 6 gal. tank in the stern, which seems to a lot of weight & fuel to be carrying around, secondly I use the boat as a dinghy for my larger boat, so I thought I might get by with a 3 gal. tank. While I'm asking questions, what size battery do this motor need for starting? It currently has a new group 24....which seem overkill & heavy!
Thanks muchly for any input.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: fuel burn ?

Leave the group 24 battery in the boat, you'll save your starter mtr. The old rule of thumb for fuel consumption was 10 % of hp at wot = gph. Meaning yours would burn 2 gph at wot. If your just using it for a dinghy you should have no prob with a 3 gal tank.
 
Top