Ribeye 600 fuel tank help

[sonicoid]

Hi all
Just started using my 100hp 2010 Ribeye A600. Fuel gauge is confusing me. It's a yamaha digital gauge and has 8 bars. I filled up and used 5 bars. Filled up again and put 32 litres in. Did the same again and used 5 bars and put 34 litres in. This gives me a fuel tank of far less then the stated 90 litres? Or are the gauges known to be far from accurate? I don't want to run out but would like more range than I currently have the bravery or stupidity to test.
Any help with this would be appricated. Tomorrow is my last day on the water before returning to the Midlands.
Thanks.

[ribber]

The fuel sender may not be that accurate. It may need re calibrating. But I wouldn't bother.

Best bet is to take spare jerry cans with as much fuel as you decide. Then run the under deck tank dry. That way you will know how much you refuel back to brimming it against the bar movement on the dial. Then always take a spare jerry, just in case...

Just a word of warning if and when taking the fuel sender out to check or replace. It can be rusted up with 5 screws and in a 'star' figuration. When replacing remember the orientation of the screws, it's not obvious when bent over double aligning it all up. Also, it's a little difficult to get to. The sender is bedded on a rubber/cork gasket and maybe perished when disturbed. So have new gasket at the ready.

Great youtube video out there showing how to do it.

www.youtube.com/watch?v=9altCtZTsds

I like this honest take on it. I also had the problem with the replacement screws. I had to find longer bolts from some b & q wall anchor bolts. Simple job, but a real pain.

[Sutty]

There is a far greater chance of the fuel gauge being inaccurate than Ribeye fitting the wrong size fuel tank. What you have not established is how much fuel there is when 3 bars are showing, more than likely about 55 litres.

I have had many boats with the same fuel gauge as you and they are certainly not accurate. On one of my current Cobra’s when there is one bar showing there is still 80 litres of fuel in.

What I have done is assumed the fuel tank size is as specified and use the fuel consumption option on the gauge once calibrated to establish the amount of fuel left on the tank at all times.

[paulbrown22]

A non-linear fuel gauge on a boat is a fairly common thing.

We used the Yamaha digital setup on our previous Avon, and it was similarly inaccurate - 3 bars was still over half full.

If you can drain and refill the tank, you can check it's exact capacity, and if you can watch the gauge as you fill it, get an idea of the actual readings on each level. We used to just always keep it full so we knew how much was in it before each trip.

[sonicoid]

Thanks everyone. I was hoping Ribeye hadn't made a mistake with the fuel tank but was wondering if previous owner had swapped it out at some point and fitted a smaller one. Sounds like the gauge is the issue. I shall run it down a bit and then try to empty the tank and fully refill to check.
Great advice as always. Thanks again.

[Orwell boy]

Not sure such drastic measures are needed here ,i reckon the gauge if its the 6y8 type can be reset , i think you can configure the gauge for a couple of different style sensors (maybe its been interfered with ? ) and also if i remember there is an opportuniy to re scale the results you get with the miles per gallon results on the same gauge ,try this link ,i think athough its selva its the same , my yam is us spec and works on us gallons ,and the only way i can get litres is to run with kilometres per hour
http://www.allpa.nl/media/Selva/SERV...LAN-Gauges.pdf

[lakelandterrier]

I think the thing to do is to fill the tank up at fuel barge or filling station if you can trail her, unttil the pump cuts out. Then you know you have the full 90l.
Log how many nm you do,then top the tank again. This will give a reckoner of fuel used per nm.
You can keep topping up with can, then recalibrate every so often when you can fill at a pump.

If the fuel gauge is reading from a sender in the tank it will not be accurate due to shape of tank and despite showing on a digital gauge. For an accurate digital reading you will need a digital gauge reading from the engine - this will show l used or l/hr burn rate.

I think you have an analogue tank sender displaying on a digital readout, it's not a digital calculation of fuel used, if that makes sense.

Based on boatand engine I'd estimate you'll be typically using c. 0.8-0.9 l/nm.