[C320-list] Yanmar 3Gm30 typical fuel consumption?

[Graeme Clark]

Hi all. I have a broken fuel gauge and we have logged 30 hours since tank was last filled. The local fuel supplier has had a breakdown and I'm some considerable distance from next nearest, with light to calm winds!
Trying to assess my likely remaining fuel. Of that 30 hrs a large part has been sub 1500rpm just mooring up etc
I'm thinking about 0.4 gal/hr maybe 0.5 to be conservative. I have a spare gallon can also!
Anyone have a better guess?
Thanks
Graeme
#366, currently in the Isles of Scilly!


Sent from mobile: please excuse typos etc.!

[Dick Walker]

I figure .6 per hour st 2300 rpm

Cheers



Dick Walker
740 Olive Ave.
Coronado ,CA 92118
619.435.8986

[Karl Mielenhausen]

Yanmar literature states 0.3 gpm (actually 1.1 lpm) at 1800 rpm.

Karl

[John Frost]

The spec for my 3YM30 (Note the Y) has a chart that says approximately
.3GPH @2000RPM
.4GPH@2250RPM
.6GPH@2500RPM
1.1GPH@3000RPM
1.3GPH@3250RPM
1.7GPH@3500RPM
1.9GPH@3650RPM

+
Happy Sailing! /||\
John / || \
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/ 2007 || \
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\ Lake Guntersville, AL l_
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[John Meyers]

On my 1997 3GM30 last year I got 2.2 gallons per hour for the 23 gallons
that I use all year. That was a mix rpms from 1500 to 3000. I do have a 3
big bladed feathering propeller that may have something to do with that.

John Meyers
Muskegon MI
Wind Chime #406

[Graeme Clark]

Now I'm confused! Some people saying 0.75 and others 2.2 gal per hour!
My typical average is under 0.5 but that includes a lot of gentle pottering so probably more when sustained high rom, obviously
0.75 sounds sensible. 2.2 sounds mad!
Graeme

Sent from mobile: please excuse typos etc.!

[John Meyers]

I am so sorry/dyslexic. I meant to write that I get 2.2 hours per gallon.

John Meyers

[jbrow...@yahoo.com]

Guess that's why it would be nice to have a working, accurate fuel gauge which at the moment I don't have.
Jim Brown

Sent from my iPad

[Graeme Clark]

Jim
I'm not sure such a thing exists! Working - yes, but accurate?
Ideally fitting a sight tube would be the most accurate - although inconvenient - way to determine fuel level
I think gauges as fitted as standard to 320s and other boats are pretty rough and ready and are often not linear


The PO of my boat told me that the sender was replaced with an incorrect model and that the gauge does work but only comes off the FULL mark when the tank is about half empty
By my reckoning it must be more than half empty now but I'm reluctant to keep going and find out the hard way that it never comes away from full!

Time to buy and fit a new sender unit!
At least I now know how to get the floor out that sits above the fuel tank to enable access!
Graeme
#366

Sent from mobile: please excuse typos etc.!

[Arthur Miller]

FWIW: I average .6 g/h, have used .75 g/h pushing against tide and heavy weather.
I use .75 g/h plus gage to judge time to fuel.
Art. # 680

Sent from my iPad

[jbrow...@yahoo.com]

How do you get that shelf out? I understand that you might be able to get the sender out without removing it but it looks tight. Fortunately my ac is in the port locker so all I have to move is an anchor and rode, a grill, couple of lines and 3 fenders and some stuff I probably forgot was there before removal.

There is a good fuel gauge trouble shooting guide posted by Jeff Hare on the web site
Jim Browm

Sent from my iPad

[Warren Updike]

I averaged fuel consumption over a 2 yr period and came up with 0.5gal/hr for the Perkins M30, 27HP. We usually try to run at about 26-2800rpm as that is the optimum rpm for this engine. That is the point at which fuel efficiency is maximized according to the Perkins information. (max-rpm x 0.8 is recommended cruising speed per Nigel Calder)
Engine is 22 yrs old with >2,000hrs, and you can't tell the engine is running by the color of exhaust: there is no color.

Warren and Pattie Updike
1994 C320 "Warr de Mar" #62
Middle River, Chesapeake Bay

[Rod Boer]

Warren,

We also cruise at 2800 RPM and 0.5 gallons per hour is what estimate.

Rod Boer
Odyssey, #688

[Greg Flanagan]

Exactly what I get Warren. And I measure my fuel level from the hours run. Its more reliable than the fuel gauge.


Greg
Hoop Dancer #1076

[Bill Sloane]

Last five years - 3.785438 gallons per hour. Cruise at 3,000 rpm
🐠🐠🐠🐠🐠🐠

Bill
Hull 594
Endless Summer
Olympia WA

Is that too precise???

[jbrow...@yahoo.com]

While on the fuel subject-Catalina Direct says that some 320's (after 1999) had a 28 gallon tank installed. Is that correct? Was it an option?

Jim Brown

Sent from my iPad

[Jeff Hare]

Jim,

This is not correct. There is a 28 gallon tank listed at Catalina Direct
but I am very skeptical that it can be installed without significant
alterations to the boat. The stock tank is 19 gallons in all the C320's as
far as I know.

If you're looking to replace the fuel tank and want more capacity, I have a
design on file at the tank mfgr for a 23 gallon tank that fits through the
aft cabin opening and doesn't interfere with the shelf in the starboard aft
locker. The tank walls are thicker than the stock tank, the fuel pickup,
sender and shutoff are easier to reach. You will need to modify wood frame
that keeps it from sliding around and allows you to strap it down.

I made a true scale model of the tank out of wood to find the largest tank
that would easily fit without having to alter any of the access paths. I
have lots more details on this project.

-Jeff Hare
#809 Woodbine II

[Rod Boer]

Bill,

At 3.785 gallons per hour you will only get a little over 5 and a quarter hours of motoring out of a 20 gallon tank. At 2800 RPM I easily do over 20 hours of motoring with plenty of fuel left over.

Rod Boer
Odyssey #688

[Jeff Hare]

Right, I think there's something wrong with the math? I don't believe it's possible to burn anywhere near 3.7 gals/hr in this engine. If you are pushing that much fuel through, maybe you should be seeing a rooster tail behind your boat, or you have an injector problem. That's well over 3x what the 3gm30f engine is rated to burn. :)

Just an observation...
-Jeff Hare
#809

[Millers]

I believe I saw an earlier email. Correcting a mid placed decimal pt

Sent from my iPhone

[jim brown]

Thanks Jeff.That's what I thought. I was looking at the replacement fuel senders (non float type) from Catalina Direct and that is what was on the notes in the info on the sender. They do list a sensor for the 320 with a 28 gallon tank. They also give the measurements for both the 19 and 28 gallon tank and the difference seems to be in the depth. Width and length the same on both drawings. They also mention an asymetrical hole pattern on the float type so it can only go in one way. Trying to fine our if the hole pattern on the newer style is also assymetrical.

Jim Brown

[Graeme Clark]

Final follow up on this. Having been unable to fuel the boat on our return we did so today (next time back on board) and I found my fuel consumption to average at 0.8 gal per hour for 14 hours motoring into a headwind in a moderate sea. This is about double my normal average which largely comprises motoring onto and off the dock or mooring and fifteen to twenty minutes at about 1500rpm whilst we get everything stowed and sails raised befor shutting down the engine.

Hopefully useful for someone else. It does seem a bit higher than the Westerbeke on my previous C320

Graeme
#366, 1996, England

Sent from mobile: please excuse typos etc.!

[Chris Burti]

We just finished cruising for three weeks on the Chesapeake and accumulated over 50 hours of running time. Our tach (second one) doesn't work, nor the fuel gauge. The hour meter on the tach does work.

I shoot for five knots simply because the engine sounds right to me at that speed. From memory that would equate to somewhere in the neighborhood of 2500 RPM. We averaged .51 gph consistently with one run of .60 gph.

By the end of the cruise, I had become very confident in using ½ gph to calculate fuel level in the tank.

Thanks,
Chris Burti
Commitment, #867
Farmville, NC

From: Graeme Clark