riddle me this-overflow of gas out the vent tube at top of carbs

[shaun b]

so, a month or so ago I was riding home and bike started losing power on the way, acting like it was out of gas (it shouldn't have been)...   luckly close to gas station and stopped put a couple gallons (it was at maybe half a tank in) and tried to re fire and nothing, just cranking, then smelling raw gas.

2004 gs500

looked under the carbs and gas was just pouring out as I cranked over the engine from somewhere up high, in between the carbs (couldn't see exactly where)

so, didn't have time to mess with it until last week and went to crank it before i dug into it... fuel started coming out of the vent tube (which is connected to the t connection between the carbs on top, where it looked like it was leaking before) where it is ran over by the petcock (maybe residual from what ever issue was that was just in the line that was now getting blown out??)

pulled the tank and pulled the vent tube and flexible t connection between the 2 carbs and fired it back up with the fuel that was left in the lines..... and... no leak...

didn't pull it any further apart, put it all back together and a little bit of fuel in and now its running fine, no leaks.  been firing it up and letting it run for last 4 days for a bit and a few short trips (no further than I'm willing to walk back home lol) and still no leaks and it runs fine.

I know stuff doesn't fix itself, been around stuff long enough lol.

so, what would have been causing this?   I'd had the bike worked on and carbs cleaned and balanced about 2000 miles previously and had been running fine on my 120 mile daily commute) other than a little bit of a hang at about 3000 rpms when coming back to idle, it doesn't always want to drop back to the 1000 rpm range.

floats/neadles stick open and flood the carbs?  I don't have any fuel in the oil. 

don't wanna get stuck again with the same issue, so i'd like to know the the potential why lol

thanks

[Endopotential]

Gonna guess the seals on your carb floats are leaking and thus flooding the system. 
If the air / fuel mixture is off, it would also explain your loss of power along the way.

Here's a quick way to check.  http://www.gstwin.com/float_height_check.htm

[Torstein]

I had a similar issue, fixed it by replacing the gaskets in the needle seat piece. I was getting massive fuel overflow through the hose like you are having.

[shaun b]

looks like i get to rebuild carbs

off to find some kits lol

Thanks guys.  figured it was something like that.

[gregjet]

Needle and seat for the floats. Common suzuki problem. If you are lucky may just be a bit of crap stuck in the needle/seat joint. If they are worn it will be new needle/seats and Suzuki charges a fortune for them

[The Buddha]

In 20+ years of GS carb tinkering I have seen exactly 1 with a bad float needle. Likely bad O rings @ the seat, or a stuck float or junk in the float spigot.
Cool.
Buddha.

[shaun b]

so, I finally got into the bike and pulled the carbs out to take a look.

I ended up finding fuel in the airbox also (I had just recently fired it up to check things and figure out which carb was giving the issue)  the fuel was coming out of the left side carb.

pulled it apart, and given the problem, only thing I can figure is the little plunger for the floats isn't sealing and allowing fuel to just flood in while running.... is that a correct assessment?  I really don't see what else would allow that much fuel to get in if it didn't start there.

got a rebuild kit on the way and will give them as through cleaning as I can.

hopefully that helps and gets this bike another few thousand miles down the road.