Fuel reserve problem, any ideas?

[DevilDesire]

Hello, as I was riding home an hour ago the bike stalled but I was expecting to hit reserver anyways. I switched the petcock to RES but the bike didn't want to start. Eventually it started but kept stalling and stalling.... I put it on PRI and it started like new, then back to RES and went back on the road. After 20-30 seconds it began running rough but I made it to a gas station, filled 8 litres of gas and switched it to ON. After that I had no problems.

Before the problem occured I opened the tank to check the fuel level and it was, in my opinion, lower than normal for ON position. Is there a chance that my bike was running the reserve fuel while being on ON position? Some vacuum petcock issues?

I'll be checking the fuel level and tomorrow I'm going to ride at RES to see if there is something clogged, maybe?

[Suzuki Stevo]

The hoses on the tank may be inverted? The hose on the back of the "chicken" goes to the fitting on the front of the tank, as long as the fitting on the tank is oriented so that the slot for the shutoff is reached with a long screwdriver from under the right side of the tank....cause the fitting on the tank can be inverted also.

[DevilDesire]

Well, I'll check that tomorrow but I doubt it because it had been fine so far... I did indeed disconnect and reconnect those hoses for carb cleaning and syncing but back then the bike was on reserver with very low fuel level and when I connected everything back it worked like before. I then refilled and put it back to ON with no problems. Still, going to take some fuel out of the tank tomorrow and check that.

[Suzuki Stevo]

Well, I'll check that tomorrow but I doubt it because it had been fine so far... I did indeed disconnect and reconnect those hoses for carb cleaning and syncing but back then the bike was on reserver with very low fuel level and when I connected everything back it worked like before. I then refilled and put it back to ON with no problems. Still, going to take some fuel out of the tank tomorrow and check that.

Did you buy the bike new? Cause if you bought it used anything is possible 

[gsJack]

A check of UK and AU parts fiches show the 2003 GS500 has a 44300-01D30 frame petcock which should make it the same as 01-02 models sold in US, no 03 models were sold here.  DevilDesire's 03 GS500 should be the same as our 01-02 models.

All of the tank petcocks for all years GS500/E/F are the same and the longer tube goes towards the front of the bike and it is for the reserve line.  The 01-02 (and 03 non US models appearantly) are the only ones where the gas lines cross as shown in my diagrams.  None of the diagrams in the parts fiches are correct.

[DevilDesire]

Today I rode at reserve and there was some very very little roughing at high rpm but it seemed to go away when i switched back to ON... is there any chance the reserve hose got a bit clogged?

[yamahonkawazuki]

Could be slightly obstructed or kinked. Was it light a solid rough running or a temporary one, cause it could be a faulty line as w w ll

[DevilDesire]

When it first occured it was more like obstructed but then it got like kinked... very rough at first and then not that much, it just got OK and then rough again and repeat... mostly at high rpm

[gsJack]

In my post above I mentioned the fuel lines on the 01-03 GSs were the only ones that crossed.  Once out of the many times I've reconnected the fuel lines on my 02 I got them wrong and the frame petcock was on Res when I rode off and a block or two later I ran out of gas.  Knowing the tank was on reserve I switched to ON and bike restarted.  Lines were backwards and ON was actually Res.

One other time I rode off after putting tank back on bike and again it stopped a block or two later and when I switched to reserve it started and I knew it had enough gas in tank to run on On position.  This time it turned out the point were the fuel lines crossed was directly behind the clutch cable pinching off one of the lines.  The one or two blocks was the distance it would go on gas in carbs.

Did you check your fuel lines to see if they were right according to my diagram above and not pinched anywhere?  Could be the reason for the problem here and high speed fuel flow could also be involved in the problem in your other thread regarding top speed if gearing turns out to be stock.

[BockinBboy]

Great point, Jack!  The crossed lines on the 01-02 (&03) models make it a more likely scenario of a pinched/kinked line just due to having to route it like that.  Would certainly be worth the time to check into it. 



- Bboy

[DevilDesire]

Thanks again, gsJack! I regret being so far away from you, I already owe you a couple of beers. 

I'll take the tank off as soon as I can because there is another problem there that wasn't there before. It happened when I cleaned and synced the carbs which of course included tank removal. The problem is that the throttle cable is holding somewhere and when the wheel is turned to the right hand side and the throttle is pulled it doesn't go back on it's own. When I move the wheel back to the centre it's almost ok but still holding a bit so I guess I have the cables kinked somewhere under the tank...

I will check the hoses and the throttle cables.

[gsJack]

When I put bar risers on my GSs (old man getting numb hands from leaning forward) I had that problem of engine racing when turning full lock right while parking.  Turned out I had to reroute the choke cable which is normally routed around the front of the left fork tube and was pulling the choke circuit open on right turns.

Too late for the I had my last drink on 12-20-78 before I even started riding in 1984.   

[enrgizerbunny]

Today I rode at reserve and there was some very very little roughing at high rpm but it seemed to go away when i switched back to ON... is there any chance the reserve hose got a bit clogged?

If it runs fine on PRI, then the reserve hose shouldn't have anything wrong with it, if your 03 petcock functions like my 97, where PRI allows direct flow from the RES line/tube without vacuum. I'm assuming it functions the same- I don't know.

[DevilDesire]

Well, indeed there are only two fuel hoses on the petcock - one under ON and one at the right side of RES. Funny thing, I ran out of fuel today while being at ON, I then switched to RES but still it didn't want to run, putting it to PRI fixed the problem and I got to the nearest gas station (about 1 km away) where I put 2 litres of fuel into the tank. The weird stuff here that happens is that the bike doesn't stall while at ON with only 2 litres in it, it neither does at RES >.<. I followed the hoses without taking the tank off and there is a little "R" letter on the carb but that's where my ON hose goes so I guess I had them mixed up. Still tho, why does it run both in ON and RES without stalling when it should die if there is under 4-5 litres in the tank while being in one of the positions....?

PS: I'm going outside to take off that damned tank I can't stand it even when I think about that....

[Suzuki Stevo]

Maybe the screen in the tank is buggered up...are there any aftermarket filters added?

[DevilDesire]

No, nothing added. I now have returned from buggering with the bike and I think I fixed it. The reserve/main hose from the tank were mixed in the wrong places... I connected them according to gsJack's schemes and then emptied the carbs and tried to start while at ON with 2 litres of fuel and it didn't start. Put it at RES afterwards and tried again and the bike started and ran... no problem. Put it back at ON while running, waited about 5-10 minutes and it died, switched back to RES and it started again and it was OK.... I guess I have this problem cleared now. Thank you all for your help guys!