What is the unusable capacity in your estimation. Is it there to keep the pump covered.
Adjusting Fuel Reading
- Thread starter faithsdaddy
- Start date
I have no idea. The only way I know you can verify that for yourself if you really need to know would be to completely empty the lower tank somehow (siphon the fuel out) or remove the tank to empty it, then fill it completely and see how much gas it takes. I'm not sure how you would determine that. IMHO, none of this is necessary, and would not prove anything that would be useful from a practical standpoint. Just my thoughts.
- Joined
- Aug 19, 2015
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- Age
- 68
- Location
- Collierville TN.
- Bike
- 2012 honda ST1300
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- 8864
I filled my tank up a couple of week ago on the side stand, then put the bike on the center stand and finished toping the tank out. There was only about 2/10 or a little more you could add to the tank. Not really enough to worry about when filling the bike on the side stand compared to the center stand. I got some strange looks when I was doing this. And it would have been easier if I had a third hand.
Agreed. Thanks for your input.
Probably easier to do it in reverse.
Fill the tank full, remove the pressurized fuel line coming from the lower tank. Put on an extension piece of hose (standard vinyl tubing will work fine, will be very low pressure) and direct it into a bucket and see how much comes out when you turn on the pump. If said bucket is on a scale, measure the weight and convert to volume.
If you want to know how much you need to keep the pump covered. Do the above procedure. Then pop the top on the lower tank and pour some gas back in until the pump is submerged. Subtract that from the total amount and you have all the answers you don't need.
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August 31 2016. After 347 miles and running on fumes (I suspected) I put in 7.358 gallons. On the centerstand, always to the rim. Not my best mpg tank, but my longest in range-so far.
If you ran it out and full to the gills was 5.5 gallons somethings up. A gas pump meter would be a possibility. My personal foolishness record was 7.123
BakerBoy
It's all small stuff.
Regarding fuel pump cooling: The pump is cooled primarily by the fuel pumped through the pump, not by the fuel it is immersed in. If it is pumping fuel, it is cooled.
Likely one of the hoses between the upper/lower tank is kinked. When they're kinked, it takes a lot of time for the fuel to dribble into the lower tank. If you check the fuel level again in the upper tank 5 or 10 minutes after filling to the rim, the fuel level likely will have dropped significantly (1 to 1.5 gallons).
Good info. I will try this.
I am experiencing another problem. Bike started flashing reserve and the displayed mileage to empty tank would not go below 46 or 47. At one point the mileage was saying 61 with the bar flashing. At times the second bar would appear and then go away. I must have rode atleast 20 miles with the bar flashing. When I finally filled. It took 6.75 gallons. Any thoughts.
Dave.David
Rider
There is two hoses between the two tanks. The large one for fuel flow and a smaller one as a breather tube. If the smaller tube is clogged or the rubber hose is going bad then it blocks the air from escaping the lower tank. And with the air being blocked the gasoline can not pour down into the lower tank.
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You mean there ARE two hoses between the two tanks?
I believe Dave may be onto something here with the vent line either pinched, or clogged up at the bottom, or perhaps the smog canister is fouled.
Just fun'en ya 'bout the gwamma.
I believe gasoline is pouring into the lower tank because I drove approximately 20 miles with the flashing bar and put 6.75 gallons when filling up. Just the fact that I put in 6.75 gallons is telling me that I was running of the lower tank.
You always run off the lower tank, it's where the fuel pump is located.
But how quickly is the gas flowing from top to bottom?
But how quickly is the gas flowing from top to bottom?
Scooter
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Was all of this observed on the same ride? Or did you stop and then restart a couple of times when this was occurring? What kind of speeds were you doing?
I have observed several times where the miles remaining estimate will seem to stay around one value or even increase slightly over time. Probably more prevalent when I'm cruising at a constant speed on the highway and not too long after the miles remaining estimate first shows up...
edit to add: Once the fuel sensor in the lower tank becomes exposed and the system goes into miles remaining mode, there is always the chance that the sensor can get "splashed" with fuel again which might explain the second bar reappearing for short periods of time.
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Scooter
This space for rent...
I can claim with some authority that you had at least another 3.8 miles left in that tank. Slacker!!! :wink::duck:
For the record, I ran out of fuel twice with my 2003 many moons ago. Strangely, both times were coming home from work and at roughly the same location. Had to push the beaST about a quarter mile each time. It took 7.44 gallons the first time and 7.46 gallons the second time to refuel (at the same pump too). Always on the centerstand and to that little notch near the rim.
I have managed to get to a station and put in 7.42 gallons in my 2004. I don't think I want to beat that milestone anytime soon...
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This is good to know and the next time I get the opportunity I will try to do better. Too many short rides this season and cold temps have kept the mpg down (the ST burns a lot more fuel during cold temp and warm ups) and haven't had more than 300 mile range/tank yet.
I have discovered something that I consider a bit odd. I get better fuel mileage and seemingly less wind back pressure (stock w/s) with a passenger. I understand the more "relaxed" speeds and acceleration runs but the amount of increase on the display during two up riding seems to give some merit to the feeling of less turbulence and back pressure, so something aerodynamicly seems better. I guess only an extended trip will tell me the real story. So far the passenger hasn't felt up to it yet, but getting there. A Russel Day Long driver and pillion seat has been given a try out and gotten a favorable response.
Hey scooter, I did stop and start a few times. I was doing some city driving and then took a short 15 mile ride on rt.12 doing about 55-60. All this while I was in reserve. The miles remaining never went below 45 and sometimes even showed 61 . On occasion the second bar also appeared with the miles remaining showing as well. None of this happened before. I will monitor this closely and see what happens when I hit reserve again. I do recall back in 2014, I ran dry with the miles remaining showing 20. Since then I realized that this could not be trusted a 100%. Based on my experience with this bike, I can get 40 miles out of the reserve. The most I have gone on the interstate before filling is 320. Reserve usually kicks in at 280. Most of my interstate riding is done at 80 mph indicated, which is roughly 75 actual.
Ok here is my data for this week. Reserve kicked in after 240 miles of city driving. The miles remaining went down gradually (no abnormalities this time). With 24 miles of gas remaining per the display, I stopped and filled up to the neck with 6.89gallons. If the display is to be assumed somewhat accurate, that would mean about half a gallon of usable gas left in the tank. I doubt that I would have gone 24 miles. Although I was tempted to. I rode 40 miles in reserve.