what happens if.....

[azguzzirep]

You run your efi bike  (lets say 98 EV) completely out of gas?
I have heard there can be problems with the fuel pump if this happens, especially if the pump is an 'in the tank' type that is cooled by the gasoline.

[pete roper]

It's not a good idea but since the pump won't run if the engine isn't running it isn't really an issue.

A couple of decades ago when you had recirculating pumps that didn't cut off unless the ignition was off? Different story.

Now? Not so much.

Pete

[rodekyll]

The pump is upstream of the filter.  So if you run out of gas you suck crud into the screen of the pump.  This can plug the pump intake.  Also, when you run completely out of gas you can have a violent backfire, which can blow off throttle bodies and exhaust bits.  We get that reported here occasionally.

[Wayne Orwig]

The gasoline lubes and cools the pump, internal or external.
Try to avoid it.

But then, I have done it a dozen times on my EV, and no harm. Well, there was
 

[Texas Turnip]

Tom,
You might remember my blue 98 EV with the 4 gallon fuel cell. I ran out many times before switching to the fuel cell with no problems at 166K when I parked it. Some are lucky, but I wouldn't advise it. If I had a newer truck I'd never run it below a 1/4 tank just to be safe.

Tex

[Muley]

I have been told that the pump damage can come from it getting too hot (with no gas flow) and then quickly filling up with relatively cool gas and running it through the hot pump.  If the pump won't run without the engine running then it's a moot issue or maybe not   I would opt to let things cool down a bit before pouring in gas and cranking.

OTOH, it'll probably cool to ambient temp. by the time I've hiked to the nearest gas station which is always ten or nine miles away

[lucky phil]

The pump is upstream of the filter.  So if you run out of gas you suck crud into the screen of the pump.  This can plug the pump intake.  Also, when you run completely out of gas you can have a violent backfire, which can blow off throttle bodies and exhaust bits.  We get that reported here occasionally.

Sorry but I cant see one single piece of accurate information in this post. As for pump overheating issues, well as Pete rightly pointed out if the engine isnt running then neither is the pump, so no issue.
I've run out of fuel several times on the V11 Sport. Long down hill engine cuts out, roll to the bottom of the hill and hit the rise, engine fires up again. Repeat.
Never an issue, except for the pushing at the end.

Ciao

[Penderic]

Oh No!  Side effects may include dizziness, blurred vision, burping, swelling, sudden gas discharges, loss of nose and ear hairs, diarrhea, shortness of breath and sudden temper fits!


Remember!!! - observe polarity when replacing fuel pump lines.

[lucky phil]

Oh No!  Side effects may include dizziness, blurred vision, burping, swelling, sudden gas discharges, loss of nose and ear hairs, diarrhea, shortness of breath and sudden temper fits!


Remember!!! - observe polarity when replacing fuel pump lines.

Ethanol fuel issues?

Ciao

[rodekyll]

Sorry but I cant see one single piece of accurate information in this post. As for pump overheating issues, well as Pete rightly pointed out if the engine isnt running then neither is the pump, so no issue.
I've run out of fuel several times on the V11 Sport. Long down hill engine cuts out, roll to the bottom of the hill and hit the rise, engine fires up again. Repeat.
Never an issue, except for the pushing at the end.

Ciao

The pump is upstream of the filter.  So if you run out of gas you suck crud into the screen of the pump.  This can plug the pump intake.  Also, when you run completely out of gas you can have a violent backfire, which can blow off throttle bodies and exhaust bits.  We get that reported here occasionally.

Phil, I generally defer to your greater experience, but I'll take the opposite side here.  I've got an external system here from older EFI that the OP's bike uses that has the flow go supply - fuel pump - filter.  I've got an internal one (that seems fairly universal in the later bikes -- the kind the hose pops off of inside the tank) and it also goes supply - pump - filter - and then external connector.  Neither has the filter ahead of the pump.  At least the external type had an additional chunk catcher at the petcock.  With the internal type, the pump is a chunk's first encounter.

The bosch design has a built-in screen behind the intake barb.  It's in the specs.  The same design (same part number in some cases) has been used in fuel injection since the 70s, and they've all had them.  One trick we use to clear that screen is reversing the polarity and backflushing the pump.  There are topics here about that all the time.

Likewise, we have frequent topics about backfires blowing off throttle bodies.  Backfires are commonly associated with running out of gas.  I've had backfires when that happened severe enough to strip the drivepiece in my Convert fluid pump.

So I'd say in the context of "what can happen when an efi bike runs completely out of gas", every piece of information in that post is both realistic and verifiable.

[lucky phil]

Phil, I generally defer to your greater experience, but I'll take the opposite side here.  I've got an external system here from older EFI that the OP's bike uses that has the flow go supply - fuel pump - filter.  I've got an internal one (that seems fairly universal in the later bikes -- the kind the hose pops off of inside the tank) and it also goes supply - pump - filter - and then external connector.  Neither has the filter ahead of the pump.  At least the external type had an additional chunk catcher at the petcock.  With the internal type, the pump is a chunk's first encounter.

The bosch design has a built-in screen behind the intake barb.  It's in the specs.  The same design (same part number in some cases) has been used in fuel injection since the 70s, and they've all had them.  One trick we use to clear that screen is reversing the polarity and backflushing the pump.  There are topics here about that all the time.

Likewise, we have frequent topics about backfires blowing off throttle bodies.  Backfires are commonly associated with running out of gas.  I've had backfires when that happened severe enough to strip the drivepiece in my Convert fluid pump.

So I'd say in the context of "what can happen when an efi bike runs completely out of gas", every piece of information in that post is both realistic and verifiable.

rodekyll what I cant fathom is how running out of petrol is linked to filter/pump contamination?
Whichever system your bike has internal or external either the pump inlet or the fuel tap stand pipe remains at the same location and when the fuel level drops to that point it sucks air and the engine and the pump stop. Where's the contamination come into the equation?
As for the backfiring and blowing bits off well if that was a realistic risk and even semi common cars and bikes would be littering the sides of the roads everywhere with maniflolds and exhausts hanging off. A Guzzi is just another EFI engine like millions of others that dont blow bits off when you run out of fuel. I cant speak for the vagaries of some of the stuff that crops up on these boards but all you need to do is look around and think about it and asses the risk for yourself.
If some here want to worry themselves about blowing bits off their engine if they run out of fuel then be my guest
 

Ciao

[rodekyll]

It's been well established here and on other forums, Phil.  But keep your opinions.  They're important to you.   

[azguzzirep]

FYI, it did not happen to me. I was just thinking about it as I will be riding unfamiliar roads on my trip to Mandello and was considering  carrying a one or two liter bottle of gas on the bike.

Good discussion, though.
Tom

[Lannis]

You run your efi bike  (lets say 98 EV) completely out of gas?
I have heard there can be problems with the fuel pump if this happens, especially if the pump is an 'in the tank' type that is cooled by the gasoline.

It would seem strange to me that a vehicle would be designed such that something as likely as potentially running out of gas would damage it.

It would be like having a bike where, if you hit the starter button going down the road, that the starter would engage and destroy the flywheel.   Or that your airplane would have a "Wings Fall Off" switch right next to the headset stereo volume like Gary Larsen did.

Running out of gas isn't like running out of oil or transmission fluid.   It's something that can happen on a long trip in a big country; the bike is DESIGNED such that it will run out of gas every few hours.   Can it be that, if you forget and run it all the way down, you'll burn up your pump or something?

As if your entire electrical system would short out if you left your turn signal on too long.   Yes, I know you're SUPPOSED to turn your turn signal off, but what if you just forget?

What were they thinking?   Or is it really not an issue?

Lannis

[rodekyll]

It would seem strange to me that a vehicle would be designed such that something as likely as potentially running out of gas would damage it.

It would be like having a bike where, if you hit the starter button going down the road, that the starter would engage and destroy the flywheel.   Or that your airplane would have a "Wings Fall Off" switch right next to the headset stereo volume like Gary Larsen did.

Running out of gas isn't like running out of oil or transmission fluid.   It's something that can happen on a long trip in a big country; the bike is DESIGNED such that it will run out of gas every few hours.   Can it be that, if you forget and run it all the way down, you'll burn up your pump or something?

As if your entire electrical system would short out if you left your turn signal on too long.   Yes, I know you're SUPPOSED to turn your turn signal off, but what if you just forget?

What were they thinking?   Or is it really not an issue?

Lannis

I don't think you've really got any good comparisons there, and the starter one in particular is bad, because when a starter chronically sticks, it messes up the flywheel teeth.  I had a starter button stick with the starter engaged and couldn't hear it over the engine.  It was my volt meter headed for zero that clued me in several minutes after starting the bike.  Fun times in Valdez!   

..  .and motorcycles aren't designed to run out of gas every few hours.  If we used your logic, bikes would be lined up on the shoulders from sea to sea on account of "they're designed to do that."   They're designed to be refilled every few hours.  That's why they put a hole in the top of the tank.  So yes, it can be . . .

 . . .and the interval for servicing your other vital fluids isn't every few hours, but on a highway bike it's about every 100 hours.  So that argument is just a matter of degrees.  If you run out before a hundred hours you might not damage anything, but on the other hand, you just might.

And of course we've all read the treads where whenever the turn signal was pushed, the fuse blew.  So that's actually a fairly common experience -- probably more common than the throttle body blowing off.

But burning up the pump for lack of gas going through it, you're right, probably not.  EFI designers DID THINK, either with the Bosch-designed "double relay" or something similar to what Guzzi did with the ecu, about turning the pump off when the engine isn't spinning (and usually whenever the starter is working).  You just don't want whatever's left in the tank spraying all over the accident scene at injection pump pressure and volume.

I don't think anyone is saying that if you run out of gas all these horrible things listed in this topic will happen to you in some sort of sequence, every time.  But I think everything discussed (except maybe the fuel pump overheating) has been documented on WG as a consequence of running out of gas by folks who have experienced it.  The OP asked what could happen.  All these things are possible, and there are examples of all of them in these archives.  Some of us have never had a flat tire, or a ticket, or thrown a rod at speed.  Some of us may never have a problem from running out of gas.  ymmv

[Wayne Orwig]

It would seem strange to me that a vehicle would be designed such that something as likely as potentially running out of gas would damage it.

They use materials that have a long life when run in gasoline. To use materials like nylon or whatever that would have a longer life when run dry, it would fail quickly when operated in gasoline 100% of the time.
 

[swooshdave]

 I've had two GM fuel pumps fail from constantly running the vehicle down to E. While doing it once shouldn't have an consequences continuing to repeat the habit could leave you stranded.

[Cam3512]

Holy crap.

The bike stops, and you start walking or pushing.  No harm.  Case closed.

[Lannis]

Holy crap.

The bike stops, and you start walking or pushing.  No harm.  Case closed.

Well, unless you are in the left lane of a heavily traveled urban interstate, with a truck right next to you on the right, an SUV running up your rear end, no shoulder on either side ....

... and your bike quits.    That doesn't seem very good; matter of fact, could be harmful.

Lannis

[Cam3512]

Well, unless you are in the left lane of a heavily traveled urban interstate, with a truck right next to you on the right, an SUV running up your rear end, no shoulder on either side ....

... and your bike quits.    That doesn't seem very good; matter of fact, could be harmful.

Lannis

Happend on my Calvin on the way to the MD Rally a few years ago.  Doing 80 mph on Rt 95 in the left lane when my pump threw a hose that Jason Speaker was supposed to have replaced with the correct one.  Miraculously, when I looked right all was clear.  No trucks or cars.  Coasted to the shoulder.  Karma bell worked for me that day...

[oldbike54]

 I've run a '98 EV out of gas . It just stopped , no fireworks , put gas in , it started right up , ran fine . Also ran my Jackal out , put in gas , runs fine . Dunno .

 Dusty