bike's fine in neutral... dies in gear... ideas...?

[Arkhame]

I'm posting for a friend...

so the bike is running just fine
then on the freeway starts to feel like its running out of gas so he switches to reserve
runs fine for a few seconds, but then starts to feel like its dying, pulls over to the side of the road, and the bike dies

waits a few minutes, and he bike starts fine in reserve
if he sits there and lets it run, or revs it, in neutral, everything works,
but when he tries to put it in gear and disengage the clutch, the bike will go a for a just little bit and then dies again, no matter how much throttle

same thing happened on prime


yes, there is gas in the tank


ideas? suggestions? 

thanks!

[Egaeus]

Sounds like he's out of gas.  Some possible suggestions:

If this doesn't happen on a completely full tank, then quite probably from having the fuel lines switched.  The tank can look like it has plenty of gas when you're out.  If they are switched, then ON is drawing from RES and vice versa.  If ON is drawing from RES, then you have no reserve.  When you run out of gas, you're pretty much screwed.

If it does happen on a completely full tank, then it could be a constriction somewhere in the fuel line.  Is there a filter on the line?  If so, and it's an automotive filter, then that is probably the problem.  Most automotive filters are designed for pressurized systems, not gravity-fed systems.  They filter well, but the fuel will just trickle into the carbs, causing the condition you describe.  Remove the filter and replace it with a filter designed for gravity-fed systems.  A cellulose riding lawnmower fuel filter will work fine.

If it doesn't have a filter on it, then check the fuel flow by getting a gas can (or other appropriate container) and placing it to the left of the bike.  Detach the fuel line from the carburetor, place it in the gas can, and turn the petcock to PRI.  It should flow freely.  If "freely" isn't a word you'd use to describe it, then there is probably something else blocking the flow.  Check the system from the tank petcock screen (you can see it with good light sticking up in the tank above where the fuel lines are attached, or you can remove the tank petcock to check it) to the carburetor.  Find what's causing the problem and fix it. 

[NWDave]

Sounds like the switch for the kick stand is hayway as I assume there is a full tank of gas and it is still doing it.. can he start it in gear with the clutch in?

[Egaeus]

Sounds like the switch for the kick stand is hayway as I assume there is a full tank of gas and it is still doing it.. can he start it in gear with the clutch in?

That's what I thought at first, but he said is sputters to death instead of dying outright like the title suggested.

[94suzuki500]

^^ +1  I say not enough gas.  the bike will run without a load but once you start going its gonna die. 

[brett]

Yo, that's me she was posting for. After I got off the phone with her and put all my gear back on, I tried starting it again. It started just fine, and this time when I tried to take off it didn't die. Before I couldn't even get the clutch fully engaged in first before it would die. This time I got it up to fourth or fifth before I felt it start to sputter again. It ended up dying as well, but I built up enough momentum to make it to the offramp. I ended up pushing it up the offramp and another block to the gas station. I fill it up full, and try it with ON. It works fine. I ride it around the gas station a bit to check. Out of curiosity I flip over to RES. I ride that around for a bit too, and the bike runs perfectly. ARGH, WHAT HELL IS GOING ON?!

Here's a little more background info. When I got the bike, the fuel lines were switched. It wasn't a problem since I knew about it. I just ran on RES and switched to ON when I ran down on gas, so really the only problem was no PRI. I've done this many times, so I know what it feels like. About a month ago I took the bike into the shop for a full service, and I had them switch the fuel lines back to normal while it was in. After I got the bike back from the shop, I put it on RES for a while out of habit, and it ran fine. A gas fillup or two later, I remembered the hoses were switched so I put it to ON. Since then it's been running fine using ON exlusively. About a week after that I crashed it at the track. Since taking it into the shop, this is the first time that I've run low enough to need to switch from ON to RES. The problem is I'm pretty sure this is because of something the shop did, but I can't know for sure since I crashed as well. It was a pretty gentle lowside, so I'm 99% sure that's not what caused this.

It's not the kickstand switch. Mine is disabled, but regardless it was dying even when the kickstand was up. Also, it was a sputtering death instead of the quick kickstand death.

The thing that really gets me is that RES works fine with a full tank but dies when it's really low. When I get home I'll check for a filter, but any other suggestions?

[Egaeus]

Did you check the lines and make sure they weren't switched?

[brett]

When it was low on gas, it wouldn't start in ON no matter how long I waited, but it would in RES and PRI. I'll double-check later, but I don't see how that would happen unless the lines were in the proper order.

[natedawg120]

well with the on ans res positions, unless modified, it wouldn't matter if you let it sit cause the petcock is vacume actuated.  If cranking then you would be sucking gas down.  So if it wouldn't start from the ON position but would from the RES and PRI positions it is possable that it was just low enough to get a little gas and then as soon as you emptied the float bowls it would die.  I suspect that the fuel levels were low enough to not go down the ON pipe in the tank but it was just enough that what you stoped and tried to start again some fuel was going down the RES/PRI pipe in the gas tank.  Which would partially fill the float bowls allowing the bike to run for a bit then die.  This would probably be the case especially if it isn't acting up after you filled your bike up.

[brett]

How would that explain why the engine revs fine when not in gear but dies once I put it in gear and try to get moving? While in neutral, I revved it up to 4-5k and kept it there for a while. It kept running fine, and showed no signs of dying. Then when I went to first and tried to pull away, it would sputter and die pretty quickly. As soon as I started to engage the clutch ever so slightly, the engine RPMs would drop dramatically, far more than normal. Even if I feathered it out as gently as possible and gave it wide open throttle, it would die within a few seconds.

[John Bates]

If you low-sided maybe some trash in the tank was jarred loose and is now restricting the fuel flow.  Have you disconnected the fuel lines, one at a time, and checked for unrestricted flow?

[Egaeus]

How would that explain why the engine revs fine when not in gear but dies once I put it in gear and try to get moving? While in neutral, I revved it up to 4-5k and kept it there for a while. It kept running fine, and showed no signs of dying. Then when I went to first and tried to pull away, it would sputter and die pretty quickly. As soon as I started to engage the clutch ever so slightly, the engine RPMs would drop dramatically, far more than normal. Even if I feathered it out as gently as possible and gave it wide open throttle, it would die within a few seconds.

It still sounds like it could be a fuel flow problem to me.  You're not using much gas to keep it running even at 5k in neutral.  I'd definitely still check the fuel flow to the carburetor.

However, another possibility has occurred to me.  It could also be running too lean.  That would prevent it from getting the fuel it needs to run the engine under load while it idles fine.  A dump will shake a lot of things loose.  Something could have gotten into your carb bowls and partially blocked your jets.  I'd take the carb out, take the bowls off, and take the jets out.  Look at them and make sure that they're clear.  I find it's easiest to look at a bright light through the jet.  A film or obstruction is easily seen.

[Yankee Punker]

 ? hows the spark, you might want to check the ignition system over because it went down, but it really just sound like it ran out of gas if its running fine now and continues to run. You can find out very quickly hear that nobody likes the stealership, and you wouldn't  any of us if you found out they never even switched the lines back to normal.
And what year is your bike, you might want to check or replace some vacuum lines on the carbs and or clean them. Again when you went down you could have knocked loose some krud from inside the tank and now it has made its way into your carbs.

[papiocho]

MY bike was doing that, this entire last tank full, sounds just like yours. mine is almost stock and droped once slightly the 1st month i had it. about 1600 miles ago, so i refused to believe that it was something with the carbs or electrical. a buddy at work told me it was bad gas, so i raised the idle past 2000 and did everything i could to keep it running  down the road, went almost in circles un till i hit 144 miles and the reserve put 3.6 gallons(40mpg CRAPPPY) at a different gas station(small city there aren't many) and now its running like new  . with this gas my idle was screaming at about 4000. brought it back to 1300ish and 50 miles later no issues.

I  say bad gas.  good luck let us know what turns out

[papiocho]

Change 2

my float levels are WAY off. and there seems to be crap floating in the little bit of fuel that was in the tube.
so next week cleaning the  carbs and the tank. and see where it takes me. 

[Happytrack44]

Several simple causes not mentioned could be, Low battery performance,GS's don't like low volts, gas cap not breathing properly,vapor locking tank,(a tank bag can cause this) and a failing diode or broken ground to the diode, which is in the side stand-neutral light circuit.beware messing with carbs until you've eliminated the simple stuff. Look over your wiring for obvious problems,check battery terminals, read voltage when off and when running. Don't Panic, and always carry a towel.

Ride safe, Rob


ps; The fuel pickups in the tank are at heights such that you don't run all the gas on "on",leaving a spit hit for your reserve pickup, If you run "reserve" you can use the whole tank from top to bottom.