200 EFI fuel consumption

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shonky1

Cadet
Joined
Jun 10, 2006
Messages
6
I have just had a 6.2 meter (21foot) Alloy fishing boat built for me. It is powered by a 2006 Mercury 200 EFI outboard. I took it on its maiden voyage yesterday and was horrified at the fuel consumption, I made it back to port with only 5 gallons left in the tank and my nerves on fire. I have a Navman 3100 fuel flow guage in it and and these are the result I got.<br /><br />* 20 knots @ 4050 rpm using 48 lph (12.5 gph)<br /><br />The boat weighs 1.4 tonne dry<br />It has a 300 ltr (80 gallons) fuel tank<br />It was loaded with 3 people and about 300 kilo (650 pounds)of gear<br /><br />I cannot find stats for the enginge anywhere so I dont know if the consumption is abnormal or otherwise. I have noticed in my searches on boat tests that most 200 hp engines do substantially higher speeds for the revs used. Does it look like I need to reprop the engine or just live with it like it is. Can anyone tell me if the fuel consumption will come down once the engine runs in? The engine has done 12 hours. If anyone has any info that could help it will be greatly appriciated.
 
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alana

Seaman
Joined
Feb 3, 2006
Messages
71
Re: 200 EFI fuel consumption

you should get about 5500 revs. so i think the prop is 2 sizes to large. my 21 footer with a 115 efi 4stroke is about a tonne + 2 people and does about 2nm to the gallon
 
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gss036

Commander
Joined
Jan 18, 2003
Messages
2,914
Re: 200 EFI fuel consumption

What size prop are you running? ( I use a 14 1/2 X 17 on my 200hp Merc, 23ft WA, about 35/3600 Lbs.) fuel consumption of 10-12 gph @ 4000 RPM. 5400 rpm, 16-18 gph. You have 4050 rpm, surly that is not your top RPM, but, what you were crusing at, right?<br />It really does not matter what engine technology you have, simple physics requires so much gas to produce power/speed at higher RPMS. All the motors are going to burn 18-20 gph at wide open throttle (max RPM). The newer engines do get very good gph at lower rpm's compared to carbs. Direct inject gives the best results along with the new 4 strokers.
 
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shonky1

Cadet
Joined
Jun 10, 2006
Messages
6
Re: 200 EFI fuel consumption

Thanks for the response, <br /><br />WOT is 40 knots @ 5500, I have only used WOT for about 30 secs as I'm running it in so I dont get good consumption readings.<br />4050 rpm is the most economical and the engine purrs at that rpm. <br />I average about 1.4 nm to the gallon at this speed. <br />The prop I have on it has these numbers 48-16316 19p. Its a genuine Mercury Marine Vengance SS prop. I gather it is a 16x19? is this correct.<br />From what you are saying Gary and alana I am about on the money.<br />We use litres over here and this is the conversion I am using, is this also correct: 1 gallon [US, liquid] = 3.785 411 8 liter<br />Thanks
 
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gss036

Commander
Joined
Jan 18, 2003
Messages
2,914
Re: 200 EFI fuel consumption

I think that is about all you can expect. You sound like you are right on, if anything, maybe there is a little better mid-range prop out there. I don't know much on that end. Maybe some one with expertise might jump in here tomorrow.
 
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shonky1

Cadet
Joined
Jun 10, 2006
Messages
6
Re: 200 EFI fuel consumption

Thanks for all your help, looks like another tank is in order.
 
studlymandingo

studlymandingo

Commander
Joined
Mar 22, 2006
Messages
2,716
Re: 200 EFI fuel consumption

Fast boats use a lot of fuel! Unless you want to break out the paddle, you're gonna burn lots of petrol. The paddle is much more economical, but it'll take a lot longer to get where you are going!<br /><br />Sounds like an awesome rig!! Got any pictures to post???<br /><br />Welcome to iboats!
 
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shonky1

Cadet
Joined
Jun 10, 2006
Messages
6
Re: 200 EFI fuel consumption

give me a sec and I will reduce and post<br />it
 
Ripfence

Ripfence

Petty Officer 1st Class
Joined
Apr 29, 2006
Messages
210
Re: 200 EFI fuel consumption

I may be talking out of school here but when I first got my OptiMax 150 it burned fuel and oil like crazy for the first 10-15 or so hours then the economy seemed to improve. It could be my imagination however. <br /><br />
Originally posted by shonky1:<br /> I have just had a 6.2 meter (21foot) Alloy fishing boat built for me. It is powered by a 2006 Mercury 200 EFI outboard. I took it on its maiden voyage yesterday and was horrified at the fuel consumption, I made it back to port with only 5 gallons left in the tank and my nerves on fire. I have a Navman 3100 fuel flow guage in it and and these are the result I got.<br /><br />* 20 knots @ 4050 rpm using 48 lph (12.5 gph)<br /><br />The boat weighs 1.4 tonne dry<br />It has a 300 ltr (80 gallons) fuel tank<br />It was loaded with 3 people and about 300 kilo (650 pounds)of gear<br /><br />I cannot find stats for the enginge anywhere so I dont know if the consumption is abnormal or otherwise. I have noticed in my searches on boat tests that most 200 hp engines do substantially higher speeds for the revs used. Does it look like I need to reprop the engine or just live with it like it is. Can anyone tell me if the fuel consumption will come down once the engine runs in? The engine has done 12 hours. If anyone has any info that could help it will be greatly appriciated.
Click to expand...
 
S

shonky1

Cadet
Joined
Jun 10, 2006
Messages
6
Re: 200 EFI fuel consumption

I dont think you imagined it, I have been told the same thing
 
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