Fuel leaking from Left Carb

[knohel]

Hi Everyone,

So I'm fairly new to working on my bike, so forgive me if I don't use the correct term or verbiage right away.  I'm trying to learn as quickly and efficiently as I can.

I was out riding my bike, and it died suddenly on me.  When I came to a stop, I found out I was having gas flowing out of my left carb at a high rate, almost like that of a stream.  So I turned the fuel line off at the tank mounted petcock.  I tried to start it, but it wouldn't start.  I checked my oil, and discovered I had about 6 inches of fluid in my crank case. After talking to a mechanic at the dealership, he suggested I had a bad float pin on my left side, and it needed to be replaced.  Once I had the tank and air filter off, I checked the float and needle of my left carb.  Both appear to be in like-new condition.  Another friend suggested I check the vacuum lines, and that I blow thru the fuel lines while the carbs were upside-down (and then while they were right-side up) to check and see if the needle was seating itself correctly.  I did that, and both sides were sealing.  So I checked the vacuum diaphragm on the frame mounted petcock, and that appears to be in good condition, with no tears or rips in it that can be visibly seen.  So I reconnected my gas tank to my carburetors outside of my bike, and gas was flowing to the carbs, but they didn't seem to be overflowing or leaking.

Today, I went back out and checked it again.  This time, the left side didn't seem to seal itself completely when I performed the blow test.  And I checked to see if there was a blockage of the ventilation hose, to ensure there was no airlock happening inside the float bowls when they were sealed (which there is none).

Now I am at a loss.  Gas flows from the fuel tank to the frame-mounted petcock and from there to the carburetors.  My understanding is that unless the carbs are actively creating suction (i.e. the engine is on and running), fuel should stop at the frame-mounted petcock and not continue into the carbs.  When I connected the carbs to the fuel tank via the frame mounted petcock, fuel continued past the frame-mounted petcock and into the carbs w/o any suction being created (they weren't installed back in the bike, just simply connected outside the bike). According to my understanding, this would point to the frame-mounted petcock being bad.  But if thats the case, why didn't my float needle seat itself all the way down this morning? Are the both bad and need to be replaced?  Because of the amount of gas I've lost, I had to test this from my reserve line, not my main line from the tank. Does this affect anything?

I'm really at a loss of what I should be doing, or what I'm looking for

[adidasguy]

Frame petcock as 3 positions: ON (normal way), RES = reserve to use up the last gallon of gas in the tank and PRIME - where fuel flows with the engine off.

Do not leave in PRIME. It is there to flow fuel with the engine is off, as when you just finished working on it and the carbs are empty.

So, did you leave it in PRIME?

A float needle can be good but have dirt under it. Gas can flow out from around the brass float needle seat (there is an o-ring on it).

(A little smaller on the paragraphs for easier reading)

[knohel]

I realize that was a lot and a large paragraph, I just wanted to be sure I covered all the information that I needed to give. And cause I'm new and don't know what I'm doing, I didn't know what information was needed.  Sorry

No, I hardly ever put it on Pri.  It's almost always on "On" or "Res".

I know there is an O-ring on the bowl, but are you saying there is an O-ring between the float needle and the base plate that secures it to the floats?

I left my floats in my drip pan (it still is about half full of the gas/oil mix that came from my crankcase) while I was at work, and while they rotated and flipped around a little, they came to a rest seal-side down (top-down) and were still floating when I checked on them about 10hrs later. So I don't think they have any holes in them

And I tried to trim some of the "fat" out of my previous post, hopefully I didn't cut out any pertinent details