V85 fuel gauge remedy

[Huzo]

Today I thought to fix the ridiculous yellow light on the fuel gauge .
The other day I did a test to dry and the fuel light came on at 325 km and she ran dry at 494 km.
So I pulled the sensor out and saw this..



What you see there is the float at the “full” position.
I then lowered the float to the “empty” position and it looks like this



So figuring that a “light on” figure of 325 k in a total endurance of 500 km means the light is coming on at the 66% point of full deflection.
So to achieve a “light on figure” of 420 km, I needed to go half way between the 66% portion and the 100% portion, so I reset the arm to achieve that end and it looks like this.



I’m watching “Long Way Up” at the moment I’ll do a test tomorrow.

[Cam3512]

So Huz, are you going to confirm an all metal filter and post a picture for posterity?  I’ve seen a borescope photo, that’s. 

[Kiwi_Roy]

There is no actual switch for the light then, It never occurred to me that the V85 has a gauge.

[Huzo]

So Huz, are you going to confirm an all metal filter and post a picture for posterity?  I’ve seen a borescope photo, that’s.

I didn’t take any notice mate.
Just did the job and buttoned it up..

[Huzo]

There is no actual switch for the light then, It never occurred to me that the V85 has a gauge.

I guess there must be a circuit that goes live, but it’ll all just happen later than before.

[Huzo]

So Huz, are you going to confirm an all metal filter and post a picture for posterity?  I’ve seen a borescope photo, that’s.

Isn’t the filter, that mesh bit on the bottom ?

[Huzo]

There is no actual switch for the light then, It never occurred to me that the V85 has a gauge.

It’s a stack of bars that count down.

[Knuckle Dragger]

Isn’t the filter, that mesh bit on the bottom ?

Yep.

[Kiwi_Roy]

Isn’t the filter, that mesh bit on the bottom ?

Thats the suction screen, somewhere there must be a pressure regulator.
https://www.mgcycle.com/index.php?main_page=product_info&cPath=164&products_id=40
https://www.mgcycle.com/index.php?main_page=product_info&cPath=30&products_id=5046
Or are they both hidden inside the other white plastic part
Is there only one connection to the tank? Yes, if you relive inside the tank a return pressure reg is not required,

[Huzo]

Thats the suction screen, somewhere there must be a pressure regulator and in line filter?
https://www.mgcycle.com/index.php?main_page=product_info&cPath=164&products_id=40
https://www.mgcycle.com/index.php?main_page=product_info&cPath=30&products_id=5046
Or are they both hidden inside the other white plastic part
Is there only one connection to the tank?

Dunno KR.
I just did the float mod and threw the whole lot back in..

[Cam3512]

Isn’t the filter, that mesh bit on the bottom ?

I was referring to the FUEL filter.  I don’t see it in the photos?

[Kiwi Dave]

I don't think there is a fuel filter.

There doesn't appear to be one in the parts manual.  Unless it's called something else, but I also looked for pictures.

[Huzo]

Bumped for Dave 1068
The display stays on “full” for a couple of hundred k’s then starts counting down.
The light now comes on with about 4 litres remaining….Simples…!

[Bulldog9]

Gauges and lights are over rated.... I go off the odometer......

Back in the day, my XS1100 was sucking fumes at 120 miles if riding sedately, when on high speed Iron butt Runs, was a stop every 90 miles, 100 was pushing it.  I get 180 miles safely from the 1200 Sport, 200 on the Stornello, 140 Griso, and I have no idea on the Convert ;-)

[Kiwi_Roy]

sum ting wong
I tried comparing the 3 photographs, I even printed them out
the pictures look very similar, especially 1 and 2
Picture 3 shows the slider at the opposite end of the wire wound pot.
the gauge works by comparing the voltage from the potentiometer slider to a set point inside the dash, at some point the slider voltage is greater than the Dash Voltage.
I would wire the gauge back into the bike wiring then you will be able to move it slowly about the set point and the light will turn Off/On
The filter on this pump is on the suction side, it doesn't need a metal case to contain the pressure.
If you connect your meter between the slider wire and ground you will be able to see where the dash is set. e.g Setpoint Voltage.

[Huzo]

sum ting wong
I tried comparing the 3 photographs, I even printed them out
the pictures look very similar, especially 1 and 2
Picture 3 shows the slider at the opposite end of the wire wound pot.
the gauge works by comparing the voltage from the potentiometer slider to a set point inside the dash, at some point the slider voltage is greater than the Dash Voltage.
I would wire the gauge back into the bike wiring then you will be able to move it slowly about the set point and the light will turn Off/On
The filter on this pump is on the suction side, it doesn't need a metal case to contain the pressure.
If you connect your meter between the slider wire and ground you will be able to see where the dash is set. e.g Setpoint Voltage.

No.
1 & 2 have the arm at opposite ends of the scale.
#3 Has me a bit perplexed as well.
I think forensic examination will reveal that the arm is in the “light turns on” position in shot # 3,  but the image doesn’t do much of a job at showing it.
Anyway.
Bending the arm in the correct direction, will delay the point at which the light illuminates which is the aim.

[Kiwi_Roy]

No.
1 & 2 have the arm at opposite ends of the scale.
#3 Has me a bit perplexed as well.
I think forensic examination will reveal that the arm is in the “light turns on” position in shot # 3,  but the image doesn’t do much of a job at showing it.
Anyway.
Bending the arm in the correct direction, will delay the point at which the light illuminates which is the aim.

I think the pump would be installed vertical with the filter at bottom rotated 90 degrees from as shown so empty with the float hanging down.
it seems to have some graduation marks on the slide wire, gallons / litres perhaps or quarter scale divisions.
https://i.ibb.co/tCKxB2p/EE2-E8-BEC-80-A6-4-C48-B16-E-8-A225591-F5-E1.jpg

[Huzo]

The whole point is, that I reset the angle on the arm.
Now if memory serves and logic would bear this out, I straightened the arm an amount. Fundamentally that means you are lowering the float, thereby putting it further under the surface of the fuel.
That means the level has to drop further before the float starts to descend, thereby causing the light to illuminate later in the fuel burn.

[Wayne Orwig]

So you bent the float lower by maybe 20mm?

For those looking for the filter, it is hidden in the plastic at the end of the hose coming from the pump.

[Huzo]

So you bent the float lower by maybe 20mm?

For those looking for the filter, it is hidden in the plastic at the end of the hose coming from the pump.

Yes Wayne.
That would be about what it was. I found the “light on” point, by plugging the unit into the harness and turning the switch on. Then measured how far the float moves from that point to “empty”.
I just gave it half of that.

[Huzo]

Bumped for azccj

[sunGuzzi]

Pump discharge side filter sits in covered housing. I replaced mine at 25k...not too bad, but while there...

[Huzo]

Pump discharge side filter sits in covered housing. I replaced mine at 25k...not too bad, but while there...

I’m sorry mate, but I don’t entirely get your point.

[sunGuzzi]

Someone I thought queried the fuel filter location in your post?...that was all. Mind you I read it on my phone...so I may have cocked it up.

[ridingron]

This is as 2 for 1 bonus thread (filter and low fuel light).

[Huzo]

All good.

[DoubleThumper]

Yes Wayne.
That would be about what it was. I found the “light on” point, by plugging the unit into the harness and turning the switch on. Then measured how far the float moves from that point to “empty”.
I just gave it half of that.

Useful post Huzo.  Thanks for presenting it.

[Huzo]

Useful post Huzo.  Thanks for presenting it.

No worries DT…
It can be made to sound complicated but it isn’t.
Just drag the whole unit out, plug it into the harness and turn on the key.
Manually bring the float towards the “light on” position. It takes the computer about 20 seconds to react to a change of position, so be patient…
When you find the “light on” position, bend the arm so the float is a bit more than halfway between that position and fully empty.
Remember.
LOWERING the float, RAISES the indicator mechanism on the rheostat.
This is what you seek, you want the mechanism to think there is more fuel in the tank than there is.
That will bring the light on later by about 150 km…

[Huzo]

Gauges and lights are over rated.... I go off the odometer......

Back in the day, my XS1100 was sucking fumes at 120 miles if riding sedately, when on high speed Iron butt Runs, was a stop every 90 miles, 100 was pushing it.  I get 180 miles safely from the 1200 Sport, 200 on the Stornello, 140 Griso, and I have no idea on the Convert ;-)

Well they’re not overrated if they actually work..
Going off the ODO is fine(ish) if you are using fuel at a constant rate, but there can be 80 km of flat out, 35 km of very gentle, followed by 27.5 km of who knows what.
Ultimately you don’t have a clue and you stop for fuel and realise you had heaps left, or worse still,you run dry 8 km from the servo…
Just fix the bastard…
I had the same type of comment when I “fixed” the speedometer on my V85 from some luminaries, all the lame responses about doing mathematical calculations on the fly and get this….
“I would worry about the more important things first…”
I did and I fixed them too.
Just do it.

[Huzo]

Bumped for azccj