Has anyone noticed if the fuel gauge is directly affected by atmospheric pressure? I did a short ride today (140 miles) with a stop at a higher altitude in the middle. Not a huge change but enough to make my ears pop once, if not twice. I had a full tank at the start of the ride and a little over half a tank at the stop in the middle. We were parked for about an hour and a half for lunch. When we got ready to leave I fired up the bike and my fuel gauge needle was sitting at almost empty. I decended from our location and filled up as I was riding "two up" and thought I had burned through the tank really quickly. When I opened the cap the tank was half full as it should have been but the needle had been reading empty.

I don't know anything about the sensor for the needle so I am wondering if it is pressure related and the slightly higher altitude threw it off.

Any thoughts?

Your level indicator is a float set up in the tank and the float sits on the cap side just a little south of the cap.I think the sender takes several readings then averages them and then the sender gives a reading .That being said did you park on an incline so that the gas was mainly in the back end of the tank,If you did then the readings might be low for a bit because the first reading or readings depending on how fast you rode off after you started your bike would have been low.It is like when after a fill up it takes a while for your tank to show full it starts out at the last reading and works its way to indicating a full tank.It is setup this way because of all the sloshing that goes on in the tank while riding.Either that or your sender is fixing to head south on you..JMO...I am using the SWAG method here and as far as atmospheric pressure hhmmmm could be .Personally I rely on after I hit reserve how far can I go to get gas without having to walk..Coug

My sender went out and it was doing all kinds of things. It would register half then go to full about 20 miles down the road, then to half again. Eventually it went to all to h*ll and I replaced it.

My fuel sender went and was doing some odd moves also. Then went completely out. That's when you low fuel light will start flashing at you. It will flash eight times which means your sending unit took a dump.