ST 1300 Gas tank question

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Nope. The last quarter of a tank is your reserve, and when you're out, you're out. Two bars is the "please get gas" indicator and one bar is the "get gas now or you're going to end up pushing" indicator.

I've had mine down to the single digits and have no plans of doing that ever again.

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--Mark

Blrfl said:

I've had mine down to the single digits and have no plans of doing that ever again.

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Been there, done that. Weeks ago, I was out scrubbing my tires in and the last bar did its flashing thing, then indicated I have 30-something miles to go ...
I got a mile down the road and the bike died.

Better to have gas in the tank than to have to push that heavy bike, don't ask me how I know the ST is heavy to push!! :banghead:

fnmag said:

It's always best to keep the fuel pump immersed in fuel. The fuel helps to physically cool the pump.

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+100

But, that said, I was going for a new personal best, miles per tank and accidentally ran her dry. And I mean absolutely would-not-restart dry and she only took 7.2 gallons to top her off. That last half-gallon (20miles) is a GHOST. Don't count on it.

TourNut said:

is the miles countdown accurate?

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It is an estimate, there is no float level sensor in the lower tank.
The estimate uses it's estimate of your mpg before the thermistor in the lower tank saw air and an estimate of the fuel delivered with the fuel injector pulses.
Key word being estimate.

If you stop the bike and turn the key back on again you'll get a false optimistic miles to pushing when you start rolling.
It forgets the fuel injector pulses and has no way to know where in the lower tank the gas is. It just sees the thermistor in air not gas.
err I think that's why it's optimistic.

7.123 gallons is as close (very close) I've some to pushing it when it stopped guessing miles and said --.- , you're on your own buddy I've given you all the warning I can.

Pelagic said:

And I mean absolutely would-not-restart dry and she only took 7.2 gallons to top her off.

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I have put as much as 7.335 into mine on a single fill. I was at 340 miles on the tank. The bike was still running.

Yes... I do believe fumes were running the bike, I was long past the suggested fill time.

TourNut said:

And is the miles countdown accurate , is there a failsafe amount still left after you get counted down to zero ?

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I have found the countdown to be fairly accurate in counting to it's reserve. I'd say probably half a gallon remains, but at this point you are running on luck and nothing else. The countdown dissapears around 18 miles to go.

When I was on the count I did play with changing throttle and load conditions, the computer did reflect those changes in it's estimated miles to empty.

What has apparently mess up some folks is that if the move the bike back and forth enough to get the thermistor wet again it resets the assumed amount and recalculates the distance to empty. Then you are going to be truly not happy!

When you get to two bars, think about filling but you have time to find a station you like. At one bar it should be top priority even if only to buy a gallon to get you to a prefered station. (Not that I would ever do such a thing, well not this month at least, err... wait... I did.)

TourNut said:

I wonder if it would take more than 7.2 gallons if you gave it more time ? The lower tank has only got about a 1/2" dia. rubber tube to gravity fill it up, while the gas station filler has considerably more volume and pump pressure to get the gas in a tank quickly ; maybe the upper tank gets filled up before the lower has time to gravity feed thru a small hose ?

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I've gone to 7.2 a couple of times. If I go two days without getting gas, I'm down to the last of the lower tank. It is usually around 270+ miles.

That hose might be small, but it isn't that small... the gas flows through it quite well! So as far as the tanks go, the lower tank is filled first (goes right through the upper tank to the lower) and since the pump is in the lower tank, the gas has to get to the lower tank for it to be pumped!

I just put 7.47 gallons into mine.

Yes... it includes the amount of gas needed to fill the FI system.

DAMHIKT... or what it's like to push a ST1300 for a mile in 30 temperature uphill in dark with traffic.

One thing you may have forgotten when it takes less than 7.7 gal to fill an "empty" tank is lower tank still has some gas in it when the fuel pump starts sucking air.

I don't like the miles to empty estimate. When I get down to the last flashing bar, I switch to gallons to empty. It starts at 1.2 and starts working its way down. I've never gone below 0.5 gallons though as I'm worried about the fuel pump getting hot and failing. I almost never fill to the very tippy top of the tank but it seems to be pretty darn close to the predicted amount of fuel to fill the tank based on 7.7 gallon capacity.

[quote;1746880]Also the fuel pump is cooled by the gas, so running it really low is not the best thing to do.[/quote]

Did not know this. Thanks for posting. I'll be sure not to do this unless draining the upper tank to remove it.

[QUOTE;1746880]Remember the 7.7 gallons is the capacity of the tanks, then they put in the fuel pump etc. Also the fuel pump is cooled by the gas, so running it really low is not the best thing to do.[/QUOTE]
I could be wrong, but would think the gas pickup from (or on) the fuel pump would be located high enough so that the pump is always submerged in gas. If so, running low on gas shouldn't be an issue.

Don B said:

I could be wrong, but would think the gas pickup from (or on) the fuel pump would be located high enough so that the pump is always submerged in gas. If so, running low on gas shouldn't be an issue.

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You are right that you are wrong!



You can use more gas than will keep the pump submerged. The pump is higher than the pump suction tube.

I have replaced a couple of pumps on these bikes and can tell you a great way to empty the top and the bottom tank...just have a really large gas can if your upper tank is full!

See the yellow circle. That is the return hose connector. It is connected to a tube that goes to the bottom where the fuel pump suction tube is.



If you remove that hose, it will suck out almost everything from both tanks until you have about maybe a cup of gas left in the bottom.

Thanks for enlightening me on this topic. I assume that if I refill at or soon after the low fuel indication starts I should be relatively safe in regards to fuel pump lifespan?

Don't know if it will extend the life of the fuel pump, but it will save you from having to push a big heavy bike. :-D

T_C said:

Don't know if it will extend the life of the fuel pump, but it will save you from having to push a big heavy bike. :-D

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I have only had to push my heavy bike once after running out of gas!! :banghead: