gas leak

When I purchased the bike ('82 KZ750LTD) a few weeks ago- the low fuel indicator light was on - but I've been riding it anyway - without any problems or seeing any leaks on the ground. So today, I finally put a couple of gallons of gas in the tank and did some more riding ( probably 30 mins. or so.. ) - and parked the bike - came back about 2 hours later to discover a puddle on the ground of "brownish" thin liquid ( with the smell of gas ) under underneath the bike engnine. Any ideas ? I took it for another ride tonight - parked it and waited again. Sure enough, another puddle of the same stuff.

Why would adding gas cause this now - with no indication of anything being different the last couple of weeks?
The only that has changed (at least that I can tell ) is the tank has more gas in it.

If you haven't left the petcock on"Prime", then you probably have a petcock that is not shutting off. These have a vacuum operated petcock, when turned to "ON" it should flow no gas unless the motor is running. Also there is a float needle not sealing properly.

Any idea as to why I didn't see any leaks prior to adding additional fuel ?

Gravity weight? Is the most likely culprit, is called Head Pressure. It will show a leak as pressure builds, hot motor will add to it. Gas expands with heat, Tank vent will loose some fuel in the form of vapor.

Have you pinpointed where it leaks at? There are over flow drains at the bottom of the carb's, they should have small black hoses on them. See if 1 of the hoses is wet. Try to feel around with you hand to find the wet spot, oh that sound kinda kinky. But that is whats needed. If it is leaking higher up it could be where the fuel line goes onto the carb's, or the fuel line to the tank, or the petcock. Could be the tubes that run between each carb as well, or a float bowl gasket.
I guess it could be coming from the Tank, either a seam failing or a rust hole. Usually the rust holes would be right along the bottom. You could take the tank off and see if the leak follows it.
Oh that's right you had a bit of info on you tank, pretty rusty. What did you do to correct it?

I've not taken a closer look yet...but I will. You've listed a variety places to look...I need to refer to the manual and see where they are....(I'm a greenie at this stuff...which adds to my frustration) The leak seems to cease after a while too. Would this be due to the cooler temperature? Is the brownish color oil ? Or perhaps oil residue from the engine - the gas is picking up as it drips down to the ground?

Well if it is oil, which you stated a Brown fluid, then it would have a different viscosity to it, and a taste. Its kinda necessary sometimes to take a small taste to confirm the liquid. Oil mixed with gas will still taste and smell different than one or the other by itself.

Motor Head wrote:

Well if it is oil, which you stated a Brown fluid, then it would have a different viscosity to it, and a taste. Its kinda necessary sometimes to take a small taste to confirm the liquid. Oil mixed with gas will still taste and smell different than one or the other by itself.

:laugh: What does ATF with a dash of fork oil taste like?

I dont think I want to know what it tastes like.