05 gs 500 wont stay running

[cleve05gs500]

hi new to the forum and new to gs's. my girl bought a 05 gs 500 about a month ago and it ran fine until almost  week ago. she was riding and it started to bog out eventually cutting off.. it started but i had to keep reving it to keep it started. so I go on this forum and it led me to the carburetor. upon taking it out the airbox was half full of gas.  I again check the forum and it said to check the float needle.. My question is how do I know if the float need its bad?  also I notice the hose comming from the bottom of the airbox was clamped off someone before me did that..  so wanted to know if someone could help me.. and please save the smart ass comments.

[langhorne047]

debris is probably preventing the float from moving freely. remove the float and needle jet and clear out any debris. if you don't have one currently, put an inline fuel filter between the petcock and carbs. clean out the gas tank as well and replace the drain hose that's clamped off.

[Joolstacho]

Well buddy, you might get a few smartarse comments, but that's a small price to pay for the generous advice you'll find on here. If as you say, you're new to the forum, try not to tell us how to run things in your first post eh! Suck it up.

Anyway... First: Make sure you have a good, reliable 'fat' spark at the plugs. (the most common engine problems are spark-related not fuel/carb related, that's what 'conventional wisdom' tells us).
Obviously the airbox being half full of gas full of gas is all wrong. Trouble is, this could be caused by other things, -what I'm saying is that this could be a SYMPTOM, not the CAUSE. But certainly open up that airbox drain so at least the excess petrol can escape. But, there's a reason it's getting in there eh? Need to find that.

I would be checking (after the spark), Fuel taps, - disconnect the feed hose to carbs, and see if fuel leaks out when the engine isn't running -(stick the line into a jar overnight and see if there's fuel in it in the morning -(and do it with the bike on it's sidestand, not the centrestand). It's not uncommon to have an old fuel tap that lets fuel seep through to the carbs even when the motor isn't running, (the fuel tap vacuum system is designed to stop fuel flow to the carbs when the donk isn't running), so then it can pass fuel from the fuel tap and it seeps past worn float needle valves, through into the airbox. (Others will chip in with their thoughts I'm sure). If the float valves aren't sealing really well, and the fuel tap vacuum system isn't cutting off fuel flow properly what can happen is the fuel leaks through the leaky fuel tap, into the carbs, filling up float bowls, and because float valves are suss, fuel floods into your airbox. Before you do anything else, remove the spark plugs and wind the starter motor over for a decent time to pump out any fuel in the engine.

There will be plenty of other things to check out, others on the forum will chip in I'm sure. Hopefully there'll be a few wisecracks thrown in too !

[cleve05gs500]

alright guys. Ive changed the float needle and seating also replaced the float bowl gaskets. put everything together and she wont start. before i took it apart i marked the lines. seems like no gas is getting to carb but i dont know for sure. any suggestions?

[1034am]

is the petcock on 'prime?'

[cleve05gs500]

no its "on"

[Big Rich]

The "On" setting only flows fuel when there is a vacuum present from the carbs (and the engine is spinning over). Try flipping it to prime, but don't leave it on prime..... or you can flood your airbox.

[lucas]

I feel you.  Have you tried starting it on prime?  Or letting the bowls fill up with fuel by setting it to prime?

Is there gas in the tank? 

Did you remember to turn the valve on the tank petcock?

Double check the hoses:
http://gstwins.com/gsboard/index.php?topic=61528.msg713437#msg713437
In the diagram the dashed lines indicate that they are not visible from that angle - so the fuel line that goes to the carbs from the frame mount petcock comes off the nipple pointed toward the front wheel and is in the middle (when looking down at the petcock).  The outside nipple and the one pointed down go to the gas tank.  The nipple that points toward the front wheel that is nearest to the center of the bike and is a little smaller than the others is the vacuum line that comes off the left carb.

If those things don't work then:

You could try removing the airbox and blocking one intake at a time with your fingers.  While starting you should feel a fairly strong vacuum against your hand, I suggest you use your fingers and not your palm so you don't make a good seal and get a giant hand-hickey.  If the engine fires up from that kind of treatment I think that does indicate a fuel flow problem.  This works on my bike because I have a fuel flow problem

If all that stuff checks out then I don't know what to tell you.  Did you put the carbs back together correctly?