poor fuel economy? 5.0 liter carb

sonus

Seaman Apprentice
Joined
May 6, 2005
Messages
35
I am fairly new to boating and I am surprised at how much gas I go thru.I recently purchased a 84 aquasport with a deep vee hull,22 feet.Ithas a volvo penta 5.0 liter with a 2 barrel rochester carb.The engine seems to be well tuned and runs perfect at all speeds.I took it out three times this past week and I am estimating that I went about 65 miles.Most of it at a cruising speed of 3800-4000 RPM(WOT is 4400).I am also estimating that I used about50 gallons of gas!!! Is this normal and is there anything I can do to improve this?Thanks for any input and to all the good people out there withgood advice !You have helped me before. Thanks!
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,093
Re: poor fuel economy? 5.0 liter carb

Is this normal and is there anything I can do to improve this?
Normal,...... Ayuh,....... Well,... Reasonable anyway.................<br /><br />There's Lots of Things you can Do to Improve on your mileage,................<br />Slowing Down for starters,........<br /><br />Most boats have a "Sweet Spot",..... Just on Plane,+ Not Burning the Bank..........<br />Usually about 2900 to 3300rpms,....... Sometimes More,...........<br />If you can get Down below those #s,+ Still maintain Planing,.... That's Money Back in the Bank...............<br /><br />Of Course,..... A "Clean" boat bottom,+ a "Well Tuned" motor will Also be a Big Plus.........
 

bomar76

Lieutenant Commander
Joined
Jun 27, 2002
Messages
1,963
Re: poor fuel economy? 5.0 liter carb

Advice:<br />Boats drink fuel like nobody's business.<br />If this is a problem.....<br />Sell the boat.
 

LubeDude

Admiral
Joined
Oct 8, 2003
Messages
6,945
Re: poor fuel economy? 5.0 liter carb

Bondo has great advice, also, play with your trim just a bit, most boats can handle at least a bit of possitive trim after up and on plane. This gets a bit more boat out of the water thus less resistance. If you have trim tabs, back them most of the way off after you are planing.<br /><br />Bomar has a point also.
 

bomar76

Lieutenant Commander
Joined
Jun 27, 2002
Messages
1,963
Re: poor fuel economy? 5.0 liter carb

I would love to get 1.3 MPG in the Baja - which is what the above consumption figures.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,093
Re: poor fuel economy? 5.0 liter carb

I can get 15 or 20 Miles to the Gallon,..............<br /><br />But,.......<br />Only when I'm Trolling,.. Down Wind.......... :D
 

sonus

Seaman Apprentice
Joined
May 6, 2005
Messages
35
Re: poor fuel economy? 5.0 liter carb

WOW-Thanks for all the quick replies!It is a trailer boat that has never been painted and I will do my best to keep it running good.Maybe I'll even slow down a bit.Anyway,I'll just keep filling that tank and smile the whole time I'm burning it!It's the American way! I just wanted to know if this fell under "normal" usage. Thanks for the input.
 

tommays

Admiral
Joined
Jul 4, 2004
Messages
6,768
Re: poor fuel economy? 5.0 liter carb

gotta love my 3.0 getting 5 MPG ;) <br /><br />tommays
 

rbezdon

Senior Chief Petty Officer
Joined
Jun 20, 2004
Messages
689
Re: poor fuel economy? 5.0 liter carb

I have an 88 5.7 and I get a bit better than what you post but I ruin at the sweet spot, about 25 to 28 MPH at about 2800 RPM. If I run at the speed you usually run, I get pretty nmuch the same as you do. I have an 88 Bayliner, about 19 foot and almost 3000lbs. According to the owners manual at 4300 RPM 45MPH it uses 19 gallons per hour. Just slow down, much easier on the wallet.
 
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