Really need to do something about this gas thing...

[JPaganel]

So, a couple of weeks ago I found out that my fuel warning doesn't actually work. It used to, but now it doesn't light at all.  Naturally, this involved parking on the shoulder at night and walking to a gas station.

So I started resetting the trip odometer at fillups. I was kinda thinking that I had about 200 miles in the tank.  Ran out at 145, about 200 feet from work.  Never mind, I figured. Maybe the mileage isn't what I think.

Today I ran out at 125.

Either the fuel mileage on this thing is total crap, or the odometer isn't particularly reliable. I could, of course, fill up every other day, but this seems inconvenient.

So, what's the wisdom on fuel floats and odometers?

[Laitch]

I'd take the primitive course of running the moto on an interstate and counting mile markers to determine if the odometer is accurate. From what I've read, Karamba—via rbm's tutorial—also could be used to determine if the odometer is working.

You can try inspecting and cleaning the fuel sender according to  rbm's fuel sender tutorial.

[billday]

Karamba is totally worth the time and trouble to use. . . . But I'm not sure it works to calibrate the odometer.

My fuel warning light has never been reliable. I refill when the trip odo hits 150.

[Billk]

I too fill up at  150 miles to be safe. I was also safe at 175 miles but I wanted the fuel pump to still be under fuel in the tank so I adapted the 150 mile marker. I did test the bike when I first got it and I ran it dry under 200 miles when she conked out.  Of course, I was carrying a small 2 1/2 gallon lawn mover fill up can as a passenger with me. I read it’s not a good idea to run the gas pump in the tank low. It should always be submerged in gas.

[natalena]

I'm with Billk, et al. in making sure the tank is always full, but it's for an entirely different reason.

Lived in AK, CA and overseas, where you always kept the fuel topped off in case of emergencies or shortages. Taught my daughter that, and she was the only person at her workplace that had a full tank of gas for evacuation during the Santa Rosa wildfire.

On topic; my trip/odometer has never been accurate (tire changes, etc.), and neither has the fuel gauge. They're only good for guesstimates.

[stokester]

I'm used to using a petcock to know when I need fuel but a quick glance at the trip meter will tell me where I'm at before passing that gas station.

This is how I handle the K75, the fuel light is just an indicator that comes on about 130 miles.  I still rely on the trip meter on my '94 and a bike computer on my '93 (trip meter does not work) to gauge the number of miles I have until a fuel stop.  Yup, about 150 miles is a comfortable fuel stop but that fuel lamp is a good reminder that a fuel stop is required soon.

[daveson]

If it's leaking while parked it would be noticeable by smell in an enclosed garage. A piece of plastic under might help. It might be leaking while riding.

[Filmcamera]

I use the old fashioned method and above 125 miles open the filler gap and have a peak.. 150 is safe to refill 175 not so and by 190 I am in major pucker factor. I also carry a reserve of 800 ml of gas in the tail which is probably good for 10 km

[Scott]

My light starts to activate at around 150 miles and stays on solid at 158 miles or so.  I've been getting about 46 mpg, mixed riding.  This is my first fuel pump, FI motorcycle. I'm more comfortable with a gravity fuel feed bike with manual petcock, or petcocks as in my airhead's case.

[The Mighty Gryphon]

I have had four bricks now(two four valve K100's, a K75S, and a K75RT) and all of them have had similar fuel consumption behavior.   The K100's with Motronic get a pretty consistent 48 to 50 mpg and have the low fuel light come on around 190 to 200 miles with about a gallon and a bit left in the tank. 

The K75's get a consistent 45-48 MPG when commuting and about 38-40 mpg when being flogged on the slab at 85-90 mph.  The K75's have the low fuel when there is about 1.5 gallons left in the tank.  Again, they light up around 185-190 miles pretty consistently. 

I have removed the flapper from all the tanks and fill to the bottom of the filler every time and always make a mental note of the amount of fuel I put in the tank as well as the tripmeter reading.  When I get a new bike I'll drain the tank and add fuel a little at a time until I get the engine to run.   Then I fill the tank to the filler ring and note how much fuel I put in.  That tells me the useful capacity of the tank.  On my bikes, that is just a bit more than 5.1 gallons.   When traveling I watch the tripmeter, and calculate how much fuel I will need when I stop for gas and how much further I can go.  About 210 miles is the farthest I'll willingly go on a full tank. 

Being a reformed enduro rider, I'm constantly calculating something in my head.  As Laitch mentioned, I check the odometer and tripmeter against mileposts, I calculate arrival times and distances, fuel use, fuel expenses, and on and on.  Riding around town and commuting, I always calculate fuel mileage when I fill up.  Most of my commuting is pretty routine, so I can predict and plan fuel stops. 

[Laitch]

I set my fuel level sender light to activate at approximately 170 miles. As natalena suggests, that 170 I've set for the warning light doesn't actually mean exactly one hundred seventy miles; it means fill the feckin tank. I follow Gryphon's routine. I prefer fuel injection to carburation because it has proven more reliable in my experience with autos and this moto.

There are plenty carburetted motos stumbling along out there with clogged jets, varnished passages, perforated floats resting on silt and leaking petcocks.
There's no romance of the open road in that for me. :giggles  :beatdeadhorse:

[Martin]

Around town running I'm getting 40 miles to the US gal with not trying to be all that economical. At steady highway speed I would expect that to go up. Years ago I tried to find the maximum range of my 75s on the highway with conservative use of the throttle and I believe it worked out to 47 miles to the US Gal. So maximum range would work out to a possible 250 miles. I never let the fuel get too low and I start looking for a service station as soon as the fuel light comes on.
Regards Martin.

[Chaos]

There are plenty carburetted motos stumbling along out there with clogged jets, varnished passages, perforated floats resting on silt and leaking petcocks.

I think the biggest advantage (maybe the only) to having a carbed bike is the reserve feature on the petcock.  The only way it usually fails is if you forget to turn it back to normal after filling up.  Too bad FI bikes don't need a petcock!

[JPaganel]

So, today I noticed that my speedometer is periodically dropping anywhere from 10-20 mph to all the way down to 0.  This might explain the odometer being off - if it isn't being turned at times, it will be low.

Speedo cable, maybe?  Is there a cable, even? I haven't looked yet.

[Martin]

There is a small black pickup sensor on the final drive, it requires periodic cleaning. If you trace the wires back from the sensor you will encounter a electrical plug which can benefit with a clean.
Regards Martin.

Speedo sensor.jpg (4.75 kB . 219x219 - viewed 472 times)

[Soggz]

There is a small black pickup sensor on the final drive, it requires periodic cleaning. If you trace the wires back from the sensor you will encounter a electrical plug which can benefit with a clean.
Regards Martin.

Speedo sensor.jpg (4.75 kB . 219x219 - viewed 472 times)

I concur. Mine didn’t work until I cleaned both ends.

[subforry]

I seem to recall my Moto Meter skipping a few miles as the plastic gear teeth broke off before it failed completely.  On my 1100 the fuel pump will scream like a banshee before it runs out of fuel.

[billday]

I read it’s not a good idea to run the gas pump in the tank low. It should always be submerged in gas.

Correct. The K bike fuel pump is both cooled and lubricated by the gasoline it's immersed in. Very bad idea to let it run dry, or even close to dry.

[stokester]

Correct. The K bike fuel pump is both cooled and lubricated by the gasoline it's immersed in. Very bad idea to let it run dry, or even close to dry.

Good advice for all in-tank fuel pumps.

[JPaganel]

There is a small black pickup sensor on the final drive, it requires periodic cleaning. If you trace the wires back from the sensor you will encounter a electrical plug which can benefit with a clean.
Regards Martin.

Speedo sensor.jpg (4.75 kB . 219x219 - viewed 472 times)

I pulled the sensor, had some crud on it.

When I went to the other end, I found the the wires had insulation peeled in a couple of spots. Put some heatshrink on it, cleaned out the connector, seems to be good so far.

[JPaganel]

Apparently, it was too early to celebrate. On the ride home the speedo was dropping again...

[daveson]

My brick had that problem once. I had to clean the three pins inside the instrument cluster, part of the green flexible circuit board. Maybe clean them, and a little twist to make for a tight connection.

[JPaganel]

Well, I guess there was another reason my gas mileage was sucking.
Went to see a friend and parked in a semi-enclosed area. Smelled gas.

Turns out the bottom clamp on the tank to rail hose loosened and was pissing gas all over my left shoe...