sputters on the freeway with plenty of gas!!! wth?!

[soon2briding]

ok.. so i was riding and i only had about 60 miles from my full tank of gas... and then all of a sudden on the freeway i feel my bike start to sputter and lose power... it felt like i ran out of gas... so i was like wth?.. so i switched it to res.. but still no help.. kept sputtering... so i turned it to prime... and then it got better... so then i get to my destination... and i open my tank.. and see i have plenty of gas... so i was like wth? and then 30 minutes later i come back to leave... and i put it on res... and it works fine... and doesnt sputter on me... what the heck is wrong? anybody know? ... oh yea.. i was going about 80-85... and it was lightly on a decline... i was riding for a bout 10 minutes before this started to happen... any help or suggestions greatly appreciated..

[Kerry]

Before swearing that you have enough gas, fill the tank and see how much you were able to put in.   :mrgreen:

If it turns out that you were down at the REServe level, then switching to the RES setting should have fixed you up.  Did you try it long enough (10-15 seconds) before switching to PRI?

If it turns out that you were BELOW the REServe level (believe me, it's deceiving!) then check to see if your ON and RES hoses are switched at the fuel tank petcock.  (See the Fuel Hose Routing photos and diagram.)

[GRU]

your lines/carbs were empty when the bike started to lose power and when you switched to RES it didn't help becuase the vacuum couldn't get enough fuel to the carbs to run at freeway speeds so then you switched to PRI and the lines filled up along with the carbs.....when you switched to PRI you couldn't have switched to RES 10 sec later and the bike would run ok but maybe not......lot's of people found out that the vacuum petcock isn't the best working at freeway speeds so some of us use PRI when we ride at 60mph +

[octane]

It wouldn't hurt to put an inline fuel filter on the bike either if you don't already have one. Saves some headaches overall. I change mine every few months and it has made a difference on my bike.

[davipu]

were you leaning on the gas cap?  i had that same problem when i went CC in June, I whould get a vacuum lock in the tank from leaning on the cap.  when the vacuum in the tank whould become equal to or greater than the manifold vacuum the carbs whould run dry.  I'd stop open the tank hit the choke and crank it for about 10 seconds and she'd start back up, kil the choke and let her idle for a couple seconds to fil the carbs and I was back on the road.

[Mountaineer]

As always, make sure the tank shuttoff valve is FULLY ON. If it is only partially on, it will do what you described.

[soon2briding]

well i didnt ride today.. so i will go home and check if my wires are hooked up wrong.. but... i rode it again yesterday and it did it again.. and this time i was for sure i had enough gas... because i filled up my gas tank right before i got on the freeway.. and i also made sure my switch was fully on "on".. so i dont know what it may be... i was leaning on my gas cap trying to avoid some wind... could that be it??... i have no clue.. but it seems it only happens at high speeds... because later on that night it happened again.. and on the freeway only it seems... so i set it on "pri" and it fixed the problem... any more ideas? or how to fix it?

and oh yea.. if my hoses are switched.. can i just leave them like that? and just put my switch on "res" for on and "on" for res?... that works right?

[Kerry]

if my hoses are switched.. can i just leave them like that? and just put my switch on "res" for on and "on" for res?... that works right?

Yep, that should work fine.

But go ahead and determine for sure whether they are switched or not.

[GRU]

take off the tank and shim the needles.....just raise them by 1 washer...

[soon2briding]

ok.. i was thinking about my hoses being switched... but im pretty sure my hoses are on right because i remember running out of gas.. and switching to reserve... so... anyways...

take off the tank and shim the needles.....just raise them by 1 washer...

i dont know how to do that... or im more like im scared to take it apart heh

[rizp]

How long have you had the bike? has it ever happened before after riding it that long at freeway speeds?

It sounds like exactly what's going on with my bike. ride it at 55+MPH for any great length of time and it starves.

if you do a search for fuel starvation you'll see an abundance of posts on the subject (including mine   )

Since reading their posts I run mine on PRI and it runs great. In fact, the starvation thing aside, I feel like it runs better on PRI than ON or RES. Just keep a track of your odometer so you know how long to go before you need a fillup. I reset my trip meter at the fuel pump every time.

There are some more involved things you could do, like switch the valve/hoses nozzles or whatever (see the other threads), but the PRI works, and best of all it's fast and free.

Hope it helps,

Regards,
Riz

[stephan]

I've gotta jump in here because the same thing has happened to me.  

I let my bike warm up, and about 10 minutes into my trip at highway speeds my bike starts to hesitate like it's running out of gas, then quits.  Both times I simply coast to the side of the highway, restart the bike and keep on going with no problem.   :dunno:

I know my hoses are right, I know I've got enough gas, I'm not leaning on my tank.  In my case I don't have time to switch the fuel selector, because the engine has already quit.  

Anymore ideas anyone!?  

[Rema1000]

Once the bike has started stuttering, I don't even bother switching from ON->RES... I go straight to PRI.  Once the bike is stalling, it's hit-or-miss whether the engine will provide a solid vacuum, with which to pull more fuel when set to reserve.

if my hoses are switched.. can i just leave them like that? and just put my switch on "res" for on and "on" for res?... that works right?

Yep, that should work fine.

Leaving the hoses backwards would have a side-effect of causing PRI to draw from the main tank (and not from the reserve tank area).  If the bike ran out of fuel from the main tank and killed, then you would be unable to fill the float bowls again.

This seems like a FAQ: people switch from ON to RES after the bike has stalled, and wonder why it won't start again.  It would save some confusion if the bike had a single gravity-fed RES/PRI setting, rather than separate settings.

[GRU]

shiming the needles is easy.....just remove the tank and then you can take off the top of the carbs.......the plastic piece on top of the carbs will have to be taken off and then you can remove the slides......flip the slides and the needle with a little plastic piece will fall out.....just put a #4 or 2 washer between the plastic piece and the needle C clip and put everything back together

there is a nice web page on shiming the needles but i can't find it....i'm sure someone else has the address to that page so please put the address here and help this guy out......i'm sure shiming the needles will help him

[Kerry]

if my hoses are switched.. can i just leave them like that? and just put my switch on "res" for on and "on" for res?... that works right?

Yep, that should work fine.

Leaving the hoses backwards would have a side-effect of causing PRI to draw from the main tank (and not from the reserve tank area).  If the bike ran out of fuel from the main tank and killed, then you would be unable to fill the float bowls again.

Yep, I thought I might have answered a little too quickly!  As far as ON and RES go it would work OK, but you're absolutely right about the PRI setting.

[Rema1000]

As far as ON and RES go it would work OK, but you're absolutely right about the PRI setting.

I had another thought, that there would still be plenty of gas in the tank; it just would not normally be reached with the PRI drawing from the upper hose.  But I bet that if you were to tip the bike to the left (even a bit, like placing it on the sidestand), then PRI would fill the bowls, and you could start the bike and switch back to ON...

But that is really overthinking through a hypothetical and very unlikely situation .

[soon2briding]

hey i have another question.. now that i was thinkging about it.. i think i rode my bike with my choke on maybe mid way... and left it on unintentionally... could this have been the cause?... is it bad to ride with choke on?... cause i think i may have done this...  :dunno:

[Rema1000]

If I leave the choke on, I usually notice when I pull the clutch in (at a stop, or to downshift) and the bike kills.  I don't think I've had it kill on me while holding a sustained throttle, but then I've not really tested leaving the choke on enough times .

[Old Mr. Wilson]

This has happened to me and here's the cure. I've been going down the road with a full tank and it would damn near die (I've had to actually pull off the road). Symptoms were EXACTLY as if it were out of gas. I now run my machine in the reserve position "all the time" and it has NEVER done that again. I understand that the GS500 has probs in this area and changing out the petcock and doing all sorts of things will correct this.
My fix was leaving it in the res. position and keeping an eye on the trip odometer (which you should do anyway). By the way, mine has only ~1475 miles (yes that's correct) on it and started that problem when it was a little baby. Mine is a year 2000 model (yes I know I should ride it more--I use mine for therapy). Hope this helps, Wilson