Leaking fuel from somewhere

Two weeks ago a buddy of mine saw my bike drip from the left carb boot to motor clamp after a short ride. Petcock was leaking and dripping on it. It only leaked in the on position. Reserve didn't seem to leak.
So I ordered a rebuild kit. I figured while the tank was apart, I'd repaint it since my previous paint job was ruined with some spilled gas.
I did the rebuild which seemed easy enough. The switch seemed a bit tight, but I figured the previous was 30 years old, so it was probably normal.

Last night I reassembled it, added some gas and went for a quick spin. Didn't see any leaks. This morning, my garage floor had the remaining gas from the tank. It was still dripping from the frame and exhaust, but the hoses,petcock and left carb are all dry. So I guess I need to add more gas and try to see where the leak is.
This sucks.

Did the gas run down into your oil ?

I don't think so? It ran all over the floor. As strange as this may sound I don't think I understand the question. I am wondering where the gas is coming from not where it went.

I am getting ready to go out and see if I can figure out where the leak is coming from. when I started this post yesterday I didn't have time to mess with the bike so I thought I'd put it out there in case somebody had an idea of where I might look.

my plan is to put some more gas in it and look for the leak, if it doesn't leak I'm going to run it and then shut it off and then watch for leaks because that would be the same as what happened the first time.

djturnz wrote: ... I am wondering where the gas is coming from not where it went....

Would sniff-test and physically examine condition of the crankcase oil to determine whether it has become contaminated with gasoline (which is a serious issue that may result from a leaking carb).

Good Fortune!

I will do that, but isn't the crank case sealed from the outside? How would it leak from the carb into the case, and on the floor?

I backed the bike into the parking lot and put it up on the center stand and I can see clearly that the gas was leaking from the bottom of the air box.I did not get as far to check the oil yet. however I am assuming that because it leaks from the air by when the bike is tilted to the rear then probably leak into the motor when it's level or to the front.

it is not looking good.

Assuming the carb floats are not installed upside down, the 3 problems described below can cause carbs to overflow. Remember - NO SMOKING or other activities that could ignite the fuel while working on carbs!

The float valve is not sealing. This may be (and probably is) just a matter of some minor dirt in the float valve and is very simple to remedy and can be done with the carbs still on the bike. Turn off fuel; drain carb by loosening big brass screw near bottom; and remove the 4 little screws on the bottom of the carb bowl. This will enable you to remove the carb bowl. You will then see the float. If you carefully remove the float you will see a stubby little needle that mates with a brass orifice; together, these two pieces are the float valve. Assuming there is no obvious damage to the needle or seat, use a Q-tip and some carb cleaner to clean the seat of the orifice and the needle. Be careful not to bend the tang that is attached to the float. This tang is the piece that the bottom of the float valve needle rests upon, and it determines the fuel level in the bowl, so bending it will change the fuel level. With the float valve cleaned it should no longer leak. To prevent a re-occurrence a quality inline fuel filter should be installed between the fuel tank and carbs. If there was damage the needle and seat should be replaced as a set; they are available.

The brass overflow tube inside the carb bowl is damaged. When you remove the carb bowl you will see a brass tube attached inside and rising toward the top of the bowl. This is the overflow tube and it leads directly to the overflow nipple on the bottom of the carb. Normally, the fuel level within the bowl rises somewhat close to the top of this tube. If the tube becomes cracked or separates from the bottom of the carb bowl fuel will flow through it and out through the overflow hose. Checking the condition of the tube is very easy after you have removed the carb bowl from the carb. Simply hold the bowl level and fill it up near the top of the tube with water of alcohol and see if it leaks. A slight crack in the brass overflow tube can be difficult to find. You can connect a rubber tube to the overflow nipple, fill the bowl with water, put finger over the open end of the brass overflow tube and blow in the rubber end and look for bubbles. If it does the best remedy is to replace it although some folks have found creative ways to repair them.

The fuel level is set too high. This condition occurs when someone has bent the float tang as mentioned above. This condition can be checked using what is referred to as the "clear tube test." The test involves attaching one end of a clear piece of flexible tubing to the carb drain hole and holding the other end of the tube above the bowl/carb joint. When the fuel is turned on it should rise in the tube to a level 2.5 - 4.5 mm below the bowl/carb joint. If the fuel rises higher than that level it may run into the cylinders or over the upper end of the brass overflow inside the carb bowl (mentioned above) in which case it will run out the overflow hose. This condition is corrected by removing the float and gently bending the tang to raise the float valve needle position. Doing this may take several tries before achieving the desired fuel level.

Correcting each of these three conditions involves removing the carb bowl. This task can be made easier if a short screwdriver bit is used, and depending on which carb you are fixing a mirror may help you locate the screws on the bottom of the carb bowl. Also, it is not a bad idea to have a new carb bowl gasket available in case the old gasket is damaged while removing the carb bowl. Ed

djturnz wrote: ... How would it leak from the carb into the case, and on the floor?

If for whatever reason gasoline rises into the carb throat, it flows both ways: (1) forward through the intake port into the combustion clamber and down around the pistons into the crankcase, and (2) backward toward the air box (and in some situations from there on down through the crankcase breather hose into the crankcase).

Good Fortune!

Be careful, you don't want any spark. Make sure the the fuel hasn't filled a cylinder. Take a moment to remove the spark plugs, rotate the motor through by hand. Engines are known to Hydro Lock, bend rods fracture pistons etc. They are supposed to compress a air and fuel mix, not a big volume of wet fuel.

the only thing that has changed since before this problem happened is that I rebuilt the petcock.
I checked my oil the level has not changed, and what I was able to extract from the case I put on a piece of metal and it will not ignite. of course this is based on the assumption that oil mix with gasoline will still ignite from a flame.

Is the tank or fuel line cracked? Could be spilling from a hole in either one that you haven't noticed

It is clearly leaking from the air box drain. I removed the tank and gas runs free, regardless of valve position. Shouldn't it do nothing in the on or reserve position when itoff the bike?