How accurate is your fuel gauge?

[FullCircle]

I have just had the embarassment of running out of fuel in 'challenging' conditions yesterday.
The Fuel gauge was still reading 1/3 full.
Usually it takes ages to get off the full mark, and I usually fill at around the half.

I dont have a dipper on the tank, as it is under the aft cabin berth, and difficult to get at.

Now, has anyone a decent method of recalibrating the sender/float thingy, and has anyone else had this issue. Its all Vetus as far as I can see.

Yours with 140 litre empty space in the fuel tank.


Jim

 

[DJE]

Mine's spot on using a translucent plastic tank and Mk.1 eyeball! /forums/images/graemlins/smile.gif

 

[raven]

A timely post Jim as I have been recently looking at installing a fuel gauge and have been trying to work out which works best and how to install.

At the moment I rely on a calibrated dip stick but am getting weary of having to lift the cabin sole and unscrew the stopper from the top of the tank to allow a reading to be taken.

However if a gauge can provide the trouble you describe, I may well decide to keep dipping.

 

[copterdoctor]

Recalibrating the fuel sensor is quite difficult (if it is possible with yours), it may be possible to adjust the gauge.

I would just mark the gauge as empty where it is showing now then a couple more marks when you fill up, say quarter and half full.
/forums/images/graemlins/smirk.gif

 

[ChrisE]

Jim,

My engine hour meter is my fuel gauge, I know that we do less than 3l/hr and keep an eye on the hours. with a 130l tank I start thinking about a top up when we've done about 35-40 hours.

 

[tcm]

i think this is best idea - use the actual fuel guage to just check that one still has a fuel tank...

 

[aluijten]

Actually mine is the other way around, when there is still 1/3 left in the tank the meter is really in the red zone (like in almost empty). On itself convenient, but it does leave you with the uncertainty after you've used 2/3: "Will I make it to the dieselstation in time"... Only to find out at the station you still have 30 litres left...

Accurate fuel gauges are not very common in the boating business as far as I can tell.

Arno

 

[FullCircle]

Chris - good idea. However, we now have the little problem of my diminishing brain, and the effects of red wine on gradual memory loss.
I guess what I need is an hours meter which I can zero each time I fill the tank. Is there one of those out there somewhere?

The hours meter on my super modern whizzo Yanmar is a tiny LCD in the lower half of the rev counter, which you need to be parallel with and squint a bit just to see it.

I am a bit miffed as it is a LEGAL requirement on cars that the fuel in the tank must be 4% of capacity when the needle is at the edge of the Zero line. Apparently not a requirement on a modern production boat built to the highest (ahem!) standards.

BTW the Yanmar 3YM30 has proved remarkably parsimonious, using just about 2L per hour so far at around 2100rpm.

 

[FullCircle]

ahh, tcm, your plan is not nearly clever enough. I have had 2 senders and 1 gauge replaced so far, so tank detection is somewhat erratic. The only way to recognise I still have a fuel tank, is when the boat fixer doesnt quite seal the top cover on the tank, and you get an olfactory alarm on descending into the cabin. Really quite effective as the alarm can still be detected 2 weeks later, even after bilgex application.

 

[Athene V30]

Jime

Make a note in your log when engine on / off and add up hours as you go. Keep running total going - know how much fuel used / how many hours to next oil change etc.

Simple and cheap - like me!

Peter

 

[FullCircle]

Arno, I would rather have your system than mine......

 

[FullCircle]

Ah, Peter, sage advice indeed, and one I already subscribe to. My engine hours are logged, but I have never been below half tank before. Therefore was not expecting interruption to propulsion service, but did recognise requirement to fill up next Thursday prior to next jaunt up the Thames.

 

[BlueSkyNick]

so come on, tell us about what happened at the time under 'challenging' conditions. How did you deal with the little bleeder?

 

[Malcb]

I have a plastic transluscent tank, which I've marked in units of 10 litres. Also on long trips I carry 20 litres in two cans so that I can top up if necessary after say 10 hours motoring. Although I only use 1.2 litres/hour /forums/images/graemlins/smile.gif

 

[cliff]

Quite accurate....

/forums/images/graemlins/laugh.gif

Joking aside, I have a sight tube up the side of the tank so easy to see how much, or little, fuel is left although I also use the "hours run" method.

There is a gauge that uses air pressure to tell you how much fuel you have left. Basically it is a very low pressure gauge and a little hand / thumb operated pump connected to a tube that goes to the bottom of the fuel tank. To read the gauge you operate the little pump to force the fuel out of the tube hence you can read the head of fuel that is left. I cannot remember the make but I am sure others will know.
--------------------

"Artificial intelligence is no match for natural stupidity"
sailroom <span style="color:red">The place to auction your previously loved boatie bits</span>

 

[Sans Bateau]

Ah! Know what that is like, my gauge lies sometimes too. But it doesn't let you know when.

First time I knew it did this was in the Little Russel with 5 knts of wind and 3 knts of tide! Luckily the tide was going the way we were going. Had I known that it was a simple case of no fuel I would have sailed against the tide and emptied the 15 ltrs of spare fuel into the tank. As it was the gauge said we still had half a tank, I think the sender unit had stuck.

 

[Koeketiene]

Ours (also Vetus) seems to hover between 60 & 75% full for a very, very long time.
Then we used about half a tank in 10 hours.

Worked out we use about 3.6ltrs/hr - I use 4ltrs/hr to be on the safe side.
So, top up every 75hrs (about once every 9 months)

 

[Judders]

I'[m a strict MkI eyeball man myself.

 

[D3B]

Never believe the little blighter and fill up when it says half. /forums/images/graemlins/cool.gif
Note how much you put in each time against the tank capacity will give you an idea of what is really happening. /forums/images/graemlins/wink.gif

think all the duff car guages are sold to boatbuilders /forums/images/graemlins/blush.gif

Glad you got back safely though

Doug

 

[Emjaytoo]

When we took delivery of our new boat the dealer said "the fuel gauge is not very accurate - don't let it go below half way". We record in the log engine hours, mileage and when we fill up.