Fuel Usage for 225 Merc's

[JimA]

New to the forum. Looks like a great resource. I'm currently looking hard at buying a Robalo 2440 Walkaround Sportfisher (deep V hull, 5,600 lbs w/o motors) with twin 1995 225hp Merc's on it. My question is, what can I expect these motors in a twin configuration to burn at different RPM's. Any thoughts would be greatly appreciated. Thanks.

 

[gss036]

Re: Fuel Usage for 225 Merc's

20-22 gallons per hr for both at cruise. 40-45 at WOT

 

[tashasdaddy]

Re: Fuel Usage for 225 Merc's

the rule of thumb is move the decimal in the hp rating to the left on place, this give you gallons per hour at wot. 225 hp 22.5 ghp. althought, reducing throttle to 3/4 7/8 increases range, economy, but slows the speed 2-4 mph. thus it takes longer to get there, so the same gas to get where you are going.

 

[phatmanmike]

Re: Fuel Usage for 225 Merc's

depends greatly on the boat and the setup. not just the motor.

are these 225 mercs you have, are these the 2.5L or are they the 3.0L?

im guessing they are prolly still the 2.5...... anywho......

i have a 1994 merc 2.5L 200hp on my 1984 mako 20C center console and i use about 22 gph at WOT , im guessing though, but i have measured my mileage before and i get about 4 mph if i cruise about 4000 rpm at which speed i'm doing about 37-38 ish mph. WOT (5600rpm) yeilds about 52 mph.
im using a stainless mercury 19P prop and i have the motor mounted up so that the anti-cav plate is 1" above the center of the bottom of the keel of the boat.

i know its not the same as yours, but its pretty close and you can use it as some good knowledge for your investment.

just as a side note, a carbed s stroke is about the worst you can get for saving fuel. i have a 2001 yamaha on my 2001 24' aquasport and it just sips fuel compaired to the mako and the carbed mercury, even though the aquasport has a dry weight of 4200lbs and the mako has a dry weight of 1700lbs.

both are 200hp, merc is 2.5L and the yammy is 2.6L , but the yammy is DFI( direct fuel injection)