4.3 gallon tank ......... NOT!!

yes, thats strange.

my 2013 Hyperstrada 821 hat real 16 liter (4.22 gal).
my new 2016 Hyperstrada 939 has only real 15 liter (3.96 gal).
specification of gas tank of both is the same, 16 liter (4.23 gal)
together with a little more gas usage than the old one i managed also to run out of gas with the 939 2 times at the beginning or our "partnership"

What bike?

My 821 Hyperstrada has had 4 gallons added a few times, without running out.

My 2015 821 has definitely taken at least 4 gallons on a few nerve wracking occasions, one time in particular I think I did nearly 80 miles with the low fuel light on.

Even when I hyper-miled my 2013 to 175 miles, I think I only replaced 3.7...and that was after driving almost 40 miles with the reserve light on.

With city/hwy use, I'll drive 10-20 miles into reserve, and normally only replace 3.2 gallons. And I always waste a couple minutes filling to rim, burping, fill, burp, etc.

Not sure how much is in there - have never reached 4 gallons even with about 40 miles of running on reserve. It won't use all of the tank because if you run the fuel pump on total empty it will burn out. Or, the tank is so weirdly shaped that ....

With the cannister removed, if I over fill and park on the sidestand, raw gas pours out. I hate that, so I'm careful.

I've always been afraid to go over 140 miles on it. Especially since the reserve light comes on so early, there's no way of knowing how much gas is really in it.

I took my 2014 hyper to the dealer for this issue when I first got my bike because there was no way the tank actually held over 4 gallons like the specs say based on my calculations. They drained it dry and filled it to the brim to measure. 3.5 gallons. Fuel light will go on after using 2.5 gallons and there is a 1 gallon reserve. Most I ever filled up at the pump was 3.2 gallons

Cdnpuck said:

I took my 2014 hyper to the dealer for this issue when I first got my bike because there was no way the tank actually held over 4 gallons like the specs say based on my calculations. They drained it dry and filled it to the brim to measure. 3.5 gallons. Fuel light will go on after using 2.5 gallons and there is a 1 gallon reserve. Most I ever filled up at the pump was 3.2 gallons

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Interesting finding. Whenever my light turns on, filling it up will be just over 3 gallons. This is with 1.1 gallon reserve; that's the theory because I've never actually tested the amount in reserve.

I do check with actual mileage as well. I'll go close to 160 miles before the light turns on, with 55+-2 mpg.

All this to say that unless the reserve is not really 1.1 gallons, mine does give me about 4.3 gallons to the tank. How could this be such a discrepancy?

edgary said:

Interesting finding. Whenever my light turns on, filling it up will be just over 3 gallons. This is with 1.1 gallon reserve; that's the theory because I've never actually tested the amount in reserve.

I do check with actual mileage as well. I'll go close to 160 miles before the light turns on, with 55+-2 mpg.

All this to say that unless the reserve is not really 1.1 gallons, mine does give me about 4.3 gallons to the tank. How could this be such a discrepancy?

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That is funny because I get right around 50mpg and my fuel light goes on around 120-130 miles traveled, at which point, I proceed to fill up for around 2.8-2.9 gallons.

Sure glad I can ride until I can refill with 4 gallons.

Appears there are variations in where the fuel pump suction draws from as there can't be that much of a difference on the tank molds.

Very strange! Surprised to see such variation in: #1. MPG #2. theoretical tank capacity #3. Actual range on reserve.

IIRC, my light comes on around 110 miles, sooner if riding hard on back roads.

I've slowly been pushing the envelope on how far I dare go before filling up.
I've yet to do my normal method for this, running it dry. (carry 1 gal. jug)

Seems running dry does risk fuel pump burning up? Does this actually happen every time someone runs out of fuel? Hard to believe. Every one runs out of gas from time to time. I would think Ducati would be swamped with law suits if this was the case.

How many have burned up their fuel pump on the Hyper from running it dry?

For me, testing started conservatively. Went 30 miles with reserve light on. Next ... pushed to 40 miles on reserve. ... and last time (before my bike BLEW UP) ... I got very close to 50 miles with light on ... it took 3.9 gallons on that last tank full.

Yet here, someone claimed 80 miles on reserve? How is such a variation possible?

Most modern, F.I. bikes have a HUGE reserve. My Tiger 1050 would run 100 miles on reserve getting 45 to 50 MPG. I tested it! When touring in Idaho, Nevada, Eastern Oregon and other remote areas you really do need to know your actual range!

I was getting close to figuring this out on my Hyper when the cam belt shredded ... game over for now. (all is being rebuilt as we speak!)

My overall "feeling" is that the Hyper does not have adequate range. I figure at best I'll get in the area of 170 miles before running dry. Not great. I'd really like to be able to go 200 miles!

But weirdest thing here is the broad variation in numbers posted here. I trust you guys and believe most everyone knows how to document MPG and such.

Can the tanks really be different? That sort of thing rarely happens on a Japanese bike.

Most logical thing is what someone said about placement of Fuel Pump
in tank. Thanks to everyone for the good input!

I commente on the fuel pump, and it was just seat of the pants - definitely defer to RSL on this. But, in general fuel pumps are cooled and lubed by fuel - this isn't a ducati thing. KTM had huge problems with theirs - don't know the cause though.

Kinda beating up an older thread but, here's what you can count on for range:
1. Slow and steady = 190
2. Shoots the gap and winds out 3 gears occasionally = 170
3. Stolen = 150

You have to account for 6-8% optimism in the speedo/ mpg calculator. Plus how aggressive you lean when it's really low; Altitude, Temp, Humidity, etc. I don't believe for a second that this fuel pump will eat itself if exposed for a short time. Maybe if you ran the tank dry routinely, but, ya know...

appliance821 said:

I commente on the fuel pump, and it was just seat of the pants - definitely defer to RSL on this. .

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Not the fuel pump because they are retained identically. The suction line though, that's what could be the difference between bikes.

I need to review the Shop Manual and parts fiche.

Fiche wasn't any help.



Service Manual isn't much help either.



Looking like they all draw from the same elevation?

I just did a trip and regularly was over 150 miles before the reserve light came on. Of course then it takes 2 gal and change. I also ran out of gas on this trip once while on reserve. My GPS has some truly erroneous ideas about where gas stations are in the fine state of NM. Good thing I had a rotopax on the back to save me.

I noticed that as I was cruising, it started to stutter and stalled. I would pull over and it was still idling. I would accelerate back up and it would start stalling again. Then I would pull over...you get the idea...

Later in my trip I was cruising up a mountain at around 8 or 9 thousand feel and it stuttered like when it was getting ready to stall. I would slow down a little and it would come back.

When the bike is hot and I stop for gas, I hear the vent trying to suck and some gurggling. Before I removed the charcoal canister, my bike (when hot) stalled and would not restart for almost an hour. Couldn't get the gas cap off either. It was a venting problem. I'm thinking we have a gas tank venting problem that is preventing the gas from being sucked (hold back is stronger than the pump suction). I'm wondering if this might explain the large disparity in our tank fill ups. We KNOW the tanks are all the same (Ducati isn't molding some tanks smaller).

Thoughts?

Haven't noticed any venting problems on my bike and it's all stock. I have noticed that the times when I get notably better mileage it's also because I am babying the bike. When I got my most recent set of new tires I was taking it really easy and hit roughly 160 if my memory serves me and started to get nervous as the fuel light hadn't come on yet. It did shortly thereafter as I pulled into a gas station.

Given we don't have a fuel gauge and are prone to get into the reserve due to that I'd suspect the fuel pump to be hardy enough to handle that. Running dry now and then probably won't kill it, but consistently doing so probably will.

I learned the hard way with my old VW TDI that trying to see how many miles you can go on reserve is a bad idea. After a month or so of owning the car and letting the car get into it's low fuel reserve I burned out my fuel pump with a full tank of diesel. Of course, had I read the manual VW was very insistent on fueling up once you hit 1/4 of a tank.

N4teTheGreat said:

Of course, had I read the manual VW was very insistent on fueling up once you hit 1/4 of a tank.

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Flawed design obviously.

With the components that go into any design: Don't pay much, Don't get much.

Over 320,000 miles on my 4Runner with running on empty warning with nearly every tank. Serious lean angles that would starve the fuel and oil pump, without good design. Never any issues.

N4teTheGreat said:

I learned the hard way with my old VW TDI that trying to see how many miles you can go on reserve is a bad idea. After a month or so of owning the car and letting the car get into it's low fuel reserve I burned out my fuel pump with a full tank of diesel. Of course, had I read the manual VW was very insistent on fueling up once you hit 1/4 of a tank.

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The early MK VI TDI's had HPFP issues. I had a 2013 that I always ran into reserve; even ran it dry once. Never had a problem in 4 years/ 70K miles. But that is BS selling a car that doesn't recommend going below 1/4 tank. Some cash strapped kids never get above 1/4...