85 KRT - fuel level dash lights

My owner's manual sez I should have two low fuel level idiot lights -- one at 7L and one at 4L. I found out yesterday that they don't work. Guess how.

Yep, outta gas. Fortunately, it ran out while I was waiting on a red light, pointing uphill. After backing downhill to get off the road, I pointed the bike down slope and got enough residual fuel to the pump to re-start the bike and make it 1/2 mile to the nearest gas station.

What fooled me into relying on the low level lights is that about 30 miles before, the red low level light had briefly come on. So, not giving it enough thought, I said to myself "ok, when the light comes on solid, I'll refuel" -- so much for the best-laid plans of mice and ...

Hopefully I'll be able to get the tank off this weekend to inspect wiring, hoses, level sender, etc. (couldn't do it this weekend, as I had to get the R100RT back together, so no playing with the KRT except to remove the battery for a load test and to remove the starter to clean the commutator). In the meantime, is there anything unique or instructive to know about an early '85's fuel level sender?

The 7L (yellow) light is known to be very unreliable - will stay on even when bike is just fuelled if the bike is warm. The 4L (red) on the other hand is generally quite reliable at 1 gallon left (40-45miles max). I'd try a couple of things. Put in a fixed known amount of fuel and see if the red one begins to respond more normally. If not than it may just need a bulb.

Or fill it all the way, ride 200-210 miles - red light should come on in that range. At best I've gotten 235 to bone dry. (Yes I have run out once in 15 years of riding this bike)

The yellow one is a whole nother story as they say. BMW engineers failed to take the heat from the engine into account when they created the sensors for these puppies, so the don't indicate as intended. I recall some sort of fix that involved a whole lot of hassel and expense, hence the reason mine didn't get fixed.

On most pods -

if you take it apart you'll find that the yellow light isn't there at all.

On my old 85 the red light came on at 1 gallon. You might want to check and see is the red light is burned out?

Both of mine still work. I have read some posts where owners found the 7L warning irritating and removed the bulb or deactivated it in some way. Not sure on the wiring but I am pretty sure you can get your hand in the tank and move the sensor. If you saw the red light blink could be as simple as a loose connection. Tanks on these are much easier to remove that the K12LT tanks are.

From memory all you have to remove is the left side glove box and the depending on the size of your hands and where the hose clamps are pointing you may be able to remove the tank.

good luck

Roy

I took both out since they turned on totally at random, and installed a Fuel+ - which was much more useful.

Thanks, all -- when I pull the tank (hopefully next weekend), I'll start with pulling the level sensor and checking out what 161K miles does to one of 'em.