The only accurate method (if you don't have a floscan) is to FILL the
tank.... run your tests and then refill your tank and note the fuel
used. Guages are never accurate enough to make fuel flow tests.

JimH wrote:
"jamesgangnc" wrote in message
ups.com...

Can't trust a gas gauge on a boat.

Fill it up. Run the engine under the conditions you want to test.
Fill it up again and see how much you had to put in it.




Using my hour meter (hours run between fill-ups) and the gallons need to
fill up I average 2.5 gallons/hour with my 20 footer powered by a 190 hp
outdrive.

10 gallons/hour for a 200 HP bass boat seems very high!