[Rickster]

The float in the bowl isn't something that usually goes bad, but the needle valve that's attached to the float is another matter. It's real comon for needle valves to get deformed, needing replacement, (it's a easy, and cheap) , or it just might have something like a speck of dirt stuck to it, keeping it from completly shuting off the gas flow, in wich case, you would just need to clean it. It's also possible that the float is out of adjustment, also easy to fix, but you need to know the proper setting, a repair manual would be real helpful for this, and any other problems that might come up.

It's also not comon for the petcock (fuel shutoff) to go bad, this is also easy to check, just disconect the hose running from the gas tank to the carb, and see if gas still runs out when it's shut. If the gas doesn't flow when it's shut, than it's fine.

You should never have water comming out of your exhaust. If I remember right, those old dirt bikes usually had an upswept pipe on them, chances are, it got some rain in it. You should try and keep this from happening, but if you get it out right away, it shouldn't hurt anything. If you can get it running, the heat from the exhaust will dry it out fine. If you can't get it running, you might want to take the pipe off, and dump it out. To keep this from happening in the future, you can just put a plastic bag over the exhaust when it looks like rain. Be sure to let the pipe cool first, if you have been running it.