My Heritage odometer tells me how many miles I have to empty. Yesterday I took a trip and filled up three times when it said it only had about 20 miles to empty, but when I filled the tank, it only took about 3.3 gallons to overflowing (well, not quite). It is supposed to hold 5 gallons. Also, I am only able to ride about 140 miles on a tank full! Any ideas?

 

I’ve had multiple brands and none of them seemed very accurate. I use the odometer.

 

Did it used to be fairly accurate....??

If so....
It could be dirt/corrosion has built up on the float sending unit (basically a potentiometer). If you run some Techron fuel additive through a few tanks full of fuel (per instructions on the bottle) it could clear it up. On the Corvette Forum some years ago, a faulty sender was a popular issue with the C5 Vettes. The additive Techron was suggested, and worked most of the time...

If it doesn't reach all the way to full on the fill ups...... It could be the float has a small leak and has taken on some fuel, causing it to not float to the top of the fuel level..

If it's been inaccurate all along...... The float arm could be bent... either form initial installation or some maintenance along the way, inside the tank.

If it bothers you enough, you could remove the sending unit from the tank, inspect it, and/or replace it.... Not hard to do..... just kind of a pain... I would be sure to have the Service manual before doing that...

For years, before getting a bike with a fuel gauge, I went by calculating my fuel mileage at fill ups and using that info, along with miles travelled (odometer), to decide when to fuel up.... I travelled many miles on bikes with a 3.5 gallon tank... never ran out of fuel...

The fuel gauges seem to be pretty close to accurate on my current softails and bagger.... close enough that I use them around town, when I rarely go below 1/4 tank.

But when on trips with long legs where I will be operating close to empty.... I still use the old fashion method of using a current calculated MPG in combo with the odometer (miles travelled) to make final decisions when to refuel, rather than the fuel gauge...

Good luck with your decision/repair...

 

I've never seen the lo-fuel warning light but at 120 miles my Low Rider gauge reads Empty. At 160, I look for fuel and typically put in 4 gallons (4.8 gallon tank.)

I ignore the gauge and reset the trip each fill up and leave it in the viewer window. (I look at the odometer only for how close to the next service I am (and that isn't very often.).

 

I am USING the odometer. It says I have 18 miles to empty, yet when I fill up with gas, it only takes 3.3 gallons to fill a 5 gallon tank.

 

I mean use it to tell you when to fill up. If you know your average miles you get out of the tank, you know when you need gas by how many miles you’ve gone. I think the fuel gauges must get sloshed around more than a car because I’ve owned Honda, Suzuki, Yamaha and HDs and none were super accurate, they’re more ballpark.

 

My 05 never worked when I bought it, had the Indy take a look but it wasn't worth the cost, now I just do the mileage thing. I can get 175 easy on a tank, then I start looking.

 

If you're filling up when it tells you you've got 20 miles left, to me that means you're using the estimated range portion of your odometer, not the odometer itself. Basically, your estimated range gauge and your overall fuel gauge should be treated as ball park guesstimates. To use your odometer, well it's gonna take some time, some miles, and some nerves of steel.

Basically, go to a station, fill your bike. Zero out your trip meters. Ride your bike as normal. Put 120 miles or so on it. Fill the tank. Make a note of how much goes in, extrapolate from that. Just to keep the math simple, 5 gallon tank, 120 miles, you fill it and put 4 gallons back in the tank. In theory you burned 4 gallons to do 120 miles so that last gallon should have given you another 30 miles. Now you've got a baseline. While you're on a ride, and you look down at your trip meter and see 120 miles, you've got approximately a gallon of gas left. Regardless of what the estimated range calculator tells you, regardless of what your gas gauge says, you're using your actual fuel level to tell you what's going on.

Now, here's where the nerve wracking part comes in. I'm not a huge fan of theory, I like to test things. So rather than trust the math, I want to know what the bike does. So, kept in areas where I knew I'd be near a station, ignored that little voice inside my head that was screaming at me to stop and fill my tank, and kept riding. It becomes a test of nerves at that point. My gas light is on, do I give in? Can I push it a little more? If I push it a little more will I have to be pushing my bike?

Basically after testing, ignoring that little voice, and carrying a emergency fuel can in my saddlebag just in case? I know at 120-130 miles on my trip meter, I have to start looking for a gas station. I don't NEED a gas station at 120 miles. I can push my bike all the way to 160-170 miles if I HAVE too. But if I start looking at the 120 mile mark? No matter what the fuel gauge and estimated trip meter says, I'll be able to get to whatever gas station I want to go too, pretty much anywhere within 40 miles, without much worry. Nothing worse than being on fumes, getting to the gas station and the pumps aren't working or it's not a 24 hour station like you thought.

 

Not knowing your history with the bike it’s unknown how well you know what is normal and what is abnormal.

My fuel economy on my 09 Heritage varies greatly depending on the type of riding I’m doing and the speeds I travel.

A couple of years ago when traveling 80 miles an hour in a strong headwind I got about 20 miles per gallon.
My Son was with me on his 2010 Heritage and he too got about 20 miles per gallon.

However cruising around the back country roads I generally get the low to mid 40s.
Running around town at intown speeds I generally get around the mid 30s.

As for the fuel gauge I have the aftermarket speedo/tach so I really can’t tell you what your gauge should show.
But on my speedo/tach when it shows 0 miles left I generally have about 3/4 of a gallon still in the tank.

 

My fuel economy on my 09 Heritage varies greatly depending on the type of riding I’m doing and the speeds I travel.

A couple of years ago when traveling 80 miles an hour in a strong headwind I got about 21 miles per gallon.
My Son was with me on his 2010 Heritage and he to get about the same, 21 miles per gallon.

However cruising around the back country roads I generally get the low to mid 40s miles per gallon.
Running around town at in town speeds are generally get around the mid 30s.

As for the fuel gauge I have the aftermarket speedo/tach so I really can’t tell you what your gauge will show.
But on my speedo/tach when it shows 0 miles left I generally have about 3/4 of a gallon still in the tank which generally means in about 25-30 miles to I’m walking.