Fuel Tank Gauge Anomoly

[Smelly]

Hi Team.

When my fuel tank is full, the guage shows half full.

What gives?

Hwo can I fix it?

THanks

[finga64]

Does the gauge show empty when the tanks empty or does it show empty when it's half empty (or is that 1/2 full?? ;))??
Adjust the float by bending the stem that holds the float. That's how it's usually done.

Before you do any bending though check the sender unit by pull the sender mechanism out and plug the sender back into the wiring and move the float through it's range of movement. Does the gauge go from full to empty??
If so it's all to do with the float adjustment. If not there's something wrong with the little coil of resistance wire in the sender unit or a loose contact in there.

Some floats also move along the stem to give more adjustment. I like these better.
I don't know which type you have.

Also by having a boo-peep at the float stem and float when it's out you should be able to gauge the range of movement to suit the depth of your tank. ie if the tank is 10' deep then the range of movement of the float should be 10' with the top limit level with the top of the tank. That's why I like the type with the float that goes along the stem. Makes this a whole lot easier. :-*
Also make sure there's no liquid or leaks in the float.

I always adjust so there is a little bit of fuel left over after the gauge says empty just as a safety margin. ;)

[Kerry]

Fuel tank gauges in boats #:-X would have to be the biggest waste of space anybody could fit ot a boat, they almost never work properly and simply not bl&&dy reliable #>:(.

Regards, Kerry.

[finga64]

Fuel tank gauges in boats #:-X would have to be the biggest waste of space anybody could fit ot a boat, they almost never work properly and simply not bl&&dy unreliable #>:(.

Regards, Kerry.

That's usually because they're hardly ever set up properly.
And I'm guessing your trying to say they're unreliable.
You just slipped in a double negative there. But we all know what you mean matey. :-*
Cheers :-*

[Kerry]

Yeah and I even read things just to make sure otherwise there's always someone waiting to pounce ;) Yes, unreliable, not reliable you've got the drift finga

[Noelm]

do you trust your gauge in your car?? I think so, then why not in your boat, just check fuel when the boat is stationary, usually on trailer in driveway, then the fuel gauge will be just as good as your car.

[TOPAZ]

Hi All,
Years ago when I decided to fit an electrical gauge to my Swiftcraft, I discovered that there were many choices of Fuel Gauge, with different resistance values when reading full/empty. I am talking VDO gauges here, and they were available in a range of values. It was ESSENTIAL to match the ohms range of the gauge with the ohms range of the sender, or no amount of bending/fiddling would get the thing to read correctly. I cannot remember the values involved, but the sender was the one to fit a Cruisetank brand tank, and the gauge was VDO.
This might be your problem.

[SgBFish]

Smelly is your boat a Quintrex?
There was an era around 2003 a lot of their senders failed where the float came off the post and floated around the tank lodging and giving false readings.

[Chimo]

Hi All

Why not re-fill the tank after every trip, and then calculate engine hours against litres added to workout litres per hour.

Then work off the engine hrs to know reasonably accurately whats used vs whats left. #

Given that no boatie would operate with less than a couple of hours fuel reserve particularly if off shore what more do you really need to know. :D

Also if there is a major change in fuel usage and the driving style is the same as usual this usually indicates somethings amiss with the motor (s)

My fuel guage is also a resonable indicator but #even on the trailer the reading varies depending if the bows up (to drain all bilge water) or level.

It and most guages have a challange to be really acccurate given the shape of fuel tanks , shallow and long with a sender at one end, on land let alone in a moving sea.

As a GOM I figure I can rely on a few things, death and taxs in particular and sorry to say fuel guages in boats really don't come even close to being worth worrying about with their "anoalitic readings and reliability".

Thats my two bobs worth, haven't run out of fuel yet and hope to keep it that way.

Cheers

Chimo

[Black_Jack]

i find the fuel flow meter a far better way to guage how much fuel has been used and how much is left. the one i use also gives me how many litres i am using an hour and how far i can go until i run out as fuel.

the fuel guage shows me that there is fuel in the tank.

geoff

[griz066]

do you trust your gauge in your car?? I think so, then why not in your boat, just check fuel when the boat is stationary, usually on trailer in driveway, then the fuel gauge will be just as good as your car.
No the one in my car does the same as the one in Smelly's boat, but the one in my boat is ok..........go figure ;D ;D ;D ;D ;D ;D

[jim_farrell]

Pick up tank, shake, estimate, = my guage.....

Jim

[Smelly]

THnaks boys - as usual fun comments!

I have a float type - Haines HUnter.

WIll try and mess with thse things on the weekedn.

FOr now, I am off to Darwin and GOve for a 3 day tour... :o

Back Sunday!

[Mr__Bean]

There is no guess work when setting up a tank guage sender unit.

There is nothing to bend, just a matter of matching the "swing length" and the "swing arc" of the float arm to the particular shape and capacity of the tank.

Not dead accurate due to tank shape, but will certainly read empty when empty and will read full when full after set up right.

Reading across the range is usually pretty close after that.

Where are you Smelly?

- Darren

[Smelly]

Melbourne based - for now

[aussiefool]

I never trust the fuel gauge in any of my boats, so what I do is cut a piece of dowl to lengh put a notch about 1cm from the end, mark where the top of the tank is and devide into 4 sections eg 1/4 1/2 3/4 and full, with the little bit at the bottom to cover water and what ever. Just dip into the tank and you know how mush fuel you have

[Mr__Bean]

Melbourne based - for now

Bugger, I was happy to come and assist but you are a bit far from Brisbane.

- Darren

[Murks]

smelly, if u have a GPS get urself a fuel flow meter and have it connected to to it.I ahave done that for the same reason as your issue, it is so accurate and you never have to worrie about LACK of fuel again
Brett

[Smelly]

Murks - I'll do that!

Give me the G O on this..

I have a Garmin 292.

How to..?

[NAGG]

I think I've only ever owned one car that had an accurate fuel gauge & trip computer (Subaru Liberty GT) .... My current Prado Grande (2006) tells me I've got 20kms left on the range ... shows empty ..... but when you fill it to overflowing you only put in 160 out of 180L :P

Now ..... How does anyone really believe that they can get an accurate reading from a boat gauge ::) ::) ::) I'll try running my new Hornet down to near empty to see how the digital gauge goes :-/
NAGG

[shanekk]

is your motor a suzuki and running the standard gauges???

cheers

[Smelly]

Murks - you got the good oil for me?

[peeler]

good info

[Murks]

sorry for the late response smelly, ;)I got mine thru the guys at qld powerboats at Loganholme, cost me $200 fitted i know they looked after me on the price but I can assure you its worth every penny.
For example, I went out christmas morning and my dial gauge showed empty whilst on the plane in flat water and about 1/4 when stopped.
my fuel gauge on my GPS told me that i had 44lt left....I went to top up my fuel and I have a 70lt tank and i filled 25lt and the boat was full :D :D...i believe it is the best investment i have made and would encourage anyone to do the same ;D ;D
Brett

[Smelly]

Murks - part description/model no. etc..

Smelly

[Murks]

Its a "fuel flowmeter " from NAVMAN with the sensor placed in the fuel line.
This is then connected back to my NAVMAN TRACKER 5380
as far as the part number I am not sure:-?
Brett :) :)

[Ron173]

Re the fuel flow meters, agree they are the go.

however you cant just connect to any gps.

Navman do their one for fitting to navman gear, lowrance do theirs too.

I have the lowrance ep10 unit, regardless of which, they operate on the NMEA2000 network, so if your gps is NMEA2000 compatable, then you can fit if not dont buy one it wont work.

I had to buy a node kit too, if its your first add on to the network, all up my add on was about $300 self fit. (a knowledge of basic electronics will help)

It measures fuel flow in ltrs/hr but because you program tank size, it can give you an accurate reading of fuel left.

Mine does log fuel per trip, total for season etc, all resettable when you choose, would recommend to anyone not happy with fuel guage.

Also as its measuring flow and remaining fuel, its not affected by swell.

Ron