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View Full Version : Fuel Economy 2004 Moomba Outback



jordydeboer1
04-22-2015, 07:51 AM
How much fuel are you guys burning per hour during normal skiing condition in a 2004 Outback? We are mostly slaloming around 28 to 30 mhp. I have the feeling I'm burning way to much and not sure what to do about it.

We just bought the boat after it sat for 3 years, we have done a lot of work on it to get it back to "as good as new" shape. BUT after using it only a few hours I have the feeling we are burning close to 9 gallons per hour?? I was expecting 6 to 7 gallons an hour during normal skiing. The motor runs beautiful and only has 185 hours on it.

Any suggestion on where to start looking?

Thank for helping A newbie!

zabooda
04-22-2015, 10:40 AM
The general consensus for the Outback was around five gallons per hour plus or minus a gallon. Nine gallons per hour would be excessive.

kaneboats
04-22-2015, 10:42 AM
You may not have it propped right for your application. If the previous owner was using it for wakeboarding and had a lower pitched prop you will have to run much higher RPM's at ski speed. So, what size/pitch prop are you running and what RPM are you running at speed?

DOCDRS
04-22-2015, 10:57 AM
My outback typically ran 30mph at 3000rpm. Although I never tracked it WOT cumsummed about 8gal per hour. I had the carbed 310 so would expect a mpi to consume less

kaneboats
04-22-2015, 11:47 AM
I think the general rule or baseline was always that a 13 x 13 prop would run 3000 RPM at 30 MPH.

zabooda
04-22-2015, 12:18 PM
I think the general rule or baseline was always that a 13 x 13 prop would run 3000 RPM at 30 MPH.
X2. Mainly for waterskiing to which it was designed.

fu-man
04-22-2015, 01:05 PM
I have the 03 outback carbed. I also agree with the 13x13 3000rpm 30mph. I can't say i have ever tried to measure fuel consumption but I'm wondering how you measured. My gas guage flops around so much it would be hard to tell exactly how much I have or how much i used.

kaneboats
04-22-2015, 01:40 PM
Fill the tank, keep track of your run time. Fill the tank again. Note the number of gallons from the second fill. That's what you burned. Divide that # by the hours elapsed run time.

zabooda
04-22-2015, 02:23 PM
. My gas guage flops around so much it would be hard to tell exactly how much I have or how much i used.

That is the reason many of us have a general idea of the consumption because the gauge is rather useless. Besides knowing on my boat that when the gauge reads "E" there is about five gallons of gas left. I just pay attention to the hour meter after a fill. Not exactly rocket science but more accurate than the gas gauge.

jordydeboer1
04-22-2015, 08:50 PM
Thanks Guys!

That is exactly what I'm doing, I filled up all the way and well see where we stand after I run 3 hour or so hours and I fill up again. The fact that that there could be 5 gallons or so left in the tank when it reads E might be why I'm concerned.

I replace the spark plugs but did not check if they were gapped correct, Have any of you seen a difference in FE after re-gapping them? (its on the to do list for tomorrow).

Thanks!

cfdrews12
04-23-2015, 01:39 PM
I've got a 2004 Outback. when skiing hard, wakeboarding or surfing, we burn in the 7 gallons an hour range just to confirm your numbers. If the boat is not missing or running rough, then you may just pull the plugs see how they look and start working down list.