Carbs leaking when bike is on?

[wirelessguy]

Before I go removing my gas tank I was curious if anyone knows the answer to this question.

5150/GS and I set and sync'd my carbs last week but it looks like now I'm getting a gas leak.

The leak drips down the carb that's attached to cylinder #2

The leak occurs even when the choke is not on but it only leaks when the bike is ON. When I shut the bike down the leak stops.

I'm not quite sure how it all works... vacuum line pulls petcock when bike turns on letting gas flow, etc...

Perhaps my gas line itself isn't tight enough or there's a leak at that union. If it were the float bowl gasket I'd think that it would leak with the bike off as well, but I'm not sure.

Any troubleshooting suggestions?

I'd prefer not to run the bike too much as I'd like to avoid flooding it.

[earlfor]

When the bike is not running, there is no engine vacuum to open the petcock, so it is closed and there is no fuel flow through it. The problem then is not the petcock.
The most likely problem is the "O" ring on the fuel inlet needle in the float bowl needs to be replaced and the float height needs to be set.

[wirelessguy]

So my issue turned out to be that the fuel hose we replaced was actually sliced open right before the T connector that goes into the carbs.

I pulled the entire hose off and cut it a bit shorter cleanly.
While the hose was removed I was getting some gas leaking out of the petcock even in Normal mode.

Question: I've reassembled everything and there is no more external leaking. I'm curious what the symtoms of a bad petcock are and if I need to flush the tank and try and clean the petcock out as well.

With the bike off, will the gas tank stop dripping gas thru the petcock into the carbs at some point or could I be leaking gas into the cylinder and down into the case? or does the gas tend to leak out of the carb air filter side beforehand? (which it's not).

Thanks.

When the bike is not running, there is no engine vacuum to open the petcock, so it is closed and there is no fuel flow through it. The problem then is not the petcock.
The most likely problem is the "O" ring on the fuel inlet needle in the float bowl needs to be replaced and the float height needs to be set.

[chuck hahn]

Take the line off at the petcock and use a spare piece of line and run it into a pop bottle. Be sure the petcock is in the ON position and let it sit a few hrs and then see if and how much fuel is collected in the bottle..if any. The "dripping" you experienced may have just been fuel inside the line dripping as you ere trimming the line back. Do this simple check tough just for the piece of mind. And you can take the vacuum line off and run that into another bottle to check that its not leaking past the vacuum diaphram as well.

[wirelessguy]

Good idea. Looks like the petcock is not leaking. It takes a bit of effort to turn so I guess that I just need to dial it just a big back form Normal toward reserve to ensure that it's not on prime. The container I set up had no gas leaking in at all.

Thanks.

[chuck hahn]

Shoot the handle in the edges with some penetrating oil and work it back and forth,,dryness is the seals enemy here!!!! Do this from time to time if you notice it stiffening up.