Fuel gauge mystery

[vaclove]

Got my bike serviced today at garage of good reputation.
When I brought the bike in, I dont remember how much fuel was left, but I am sure the tank was not empty.
When I have picked the bike, I have noticed low fuel indicator and computer showing 60 miles left. I have thought this is strange, but so be it...
I took the bike and rode about 1 mile, during which the remaining distance has going 50, 40, 30...6. I have pulled over and checked the bike. There was no obvious leakage , but I could smell fuel. I have phoned the garage and asked what the heck have they done to my bike. They claimed, nothing was done to fuel tank or so.
I walked to gas station and got 3L petrol and topped up the bike. The indicator started to show crazy things like that there is 150 miles worth of fuel etc...then it comewhat stabilized.
The bike did 22000 miles without ANY issues of this kind. While they might not done anything bad to the bike in the garage, the only observation I can make is. Before service OK, after service and computer reset not so OK.

Any ideas what might have gone wrong?

 

[ILMV]

This has happened to me a few times too.

First was whilst trying to get out of a muddy pit, was revving the bike lots but not moving... I think this confused the poor thing, perhaps it thought it was using more fuel than it was.

The second time this happened to me I killed the engine and re-started whilst rolling down a hill. Again, I think it was getting confused as to how much fuel it was using and reduced the miles remaining down to 0.

Is it still doing this or is it behaving after the re-fuel?

 

[vaclove]

more observations

I have now refueled the bike at petrol station. from the point computer showed nearly empty tank with 6 miles fuel remaining, I have put in 3L from canister and then after traveling ca 5 miles 8L more at the pump.
Considering 16L tank, there must have been 16-3-8=5L left. Now the bike behaves normally.
I am just wondering, what happens when computer shows 0 miles left. Does it stop the engine even there is still fuel in the tank?
About 2 years ago, I have reported a problem, when engine was cutting of during hot summer day. Dealer have diagnosed the problem as overheating, however, the coolant temperature was normal. Yet, the computer was detecting overheating and switched off the engine.
Another idea that came to my mind if that maybe, in the service, they have reset the fuel gauge level (I am just speculating here). So after the reset, whatever the gauge showed was level 0 and therefore falsely showing me I am out of petrol.

 

[dpm]

Given the two problems I'd be looking closely at the wiring in general and the ground points in particular. A loose or corroded connection would do this for sure.

 

[mrjim130]

Don't think it will stop when the remaining mileage is zero, mine ran out showing 40 mile range. Fuel gauge is rubbish. I use the trip computer.

 

[Dean]

I think they are all different and most cock-a-hoop

not to mention depending on the variables


I tested mine once, the tank was filled then run Dry and it run out at 218.8 miles.

The fuel light came on then 49 miles later it ran out.

when the computer showed 9 miles to empty it actually gave me 23 Miles.

on long rides using the garmin, I have set the garmin fuel gauge at 190 mile range to flag up as fail safe

It works for me

 

[rodooo]

My fuel gauge is actually very accurate. 2012 model

 

[v8legend]

FWIW, I find my fuel gauge very accurate, and have run down to zero several times. I've then managed to get between 16.3 and 16.45 litres in, so not far out.

The only time I've had an issue was once after filling up the gauge didn't show full for about 10 miles. I stopped to make sure there wasn't a leak. That's when I noticed that the fuel cap hadn't clicked fully home, it then showed full.

A few people have criticised the accuracy by saying that it doesn't move until nearly half empty. This doesn't bother me, I'm only interested in when it's going to run out.

 

[rodooo]

FWIW, I find my fuel gauge very accurate, and have run down to zero several times. I've then managed to get between 16.3 and 16.45 litres in, so not far out.

The only time I've had an issue was once after filling up the gauge didn't show full for about 10 miles. I stopped to make sure there wasn't a leak. That's when I noticed that the fuel cap hadn't clicked fully home, it then showed full.

A few people have criticised the accuracy by saying that it doesn't move until nearly half empty. This doesn't bother me, I'm only interested in when it's going to run out.

 

[smaytum]

My fuel gauge has been pretty good. There are 3 things to consider...

1) due to the shape of the tank, only the lower amount of fuel is measured, which is why our bikes say >100 miles because it can only guess the amount of fuel left when the tank is quite full. It calculates using recent average consumption only.

2) range is always calculated using recent average consumption, which is why you may have a range of 30 miles (for example) when you put the bike away after motorway riding and the next morning, that 30 miles reduces really quickly (within just a few miles).

3) when your bike was being serviced. They would have reset the computer, which means that fuel consumption must be recalibrated, so the range calculation will jump around a little for the first few miles.

Having said all the about. It still sounds odd. Could they have taken a little fuel for themselves This would mess up the range calculation for sure.

 

[MikeMike]

Did you check your bike really carefully on the right hand side to make sure they hadn't tipped it over accidentally during the servicing? Or one of the lot minions let it get out of their hands and slowly fall over?