I have a 2000 kawasaki ZR750 with a gas leak

More than likely you have a bad fuel petcock. No fuel should go from tank to carb without the engine running because the fuel is pulled by vacuum. Remove line from petcock an have it set to on or reserve position and if fuel comes out it is bad, and let's the fuel continue to flow to the carb and seep into the engine oil also. Mine was bad and had my oil thin as water with all the gas in it. Wonder it didn't wash a bearing out of the engine. Check and drain oil immediately if the petcock is bad.

the oil injection unit on these skis can fail to test you will need to empty gas tank disconnect oil feed line to inlet manifold
then make a mix of two stroke fuel to the correct ratio say 10 liters. poor in to tank and take ski for a run say 10 minutes let it rest and run again if problem persists

it is possible you have leaking or blown crank case seals you will most likely need a professional to test for
i have provided you a link for free shop manual

Sounds like a blocked breather. Be careful with all that leaked petrol.

You need to check the pipes for leaks or if its the gas tank itself you need to weld it(let it dry for at least a week) check the fuse for the gauge or trace the wiring.

Several things could be wrong. First, the fuel petcock (valve) at the bottom of the gas tank should be turned off when the bike is not being ridden. Also, it is possible the valve may not be fully shutting off the gas. This can allow the carb to overflow and leak gas. A stuck open or punctured float in the carb bowl can cause overflow. The float should be light as a feather and have nothing inside it but air. Is the carb securely mounted?

Check for cracked fuel hose or bad connections at the tank and carb. Is the fuel valve body leaking gas where it mounts to the tank? Heck, with the bike being 36 years old the tank may be leaking at a weld or due to rust through. I wish I could work on your bike. The older bikes are more fun to work on than the newer bikes. Post a reply and let me know what you find.

is it the actual gas line, or just the tank over flow ,, if you filled the tank to much it will leak out a little

It sounds like that hose which runs fron the cap area (inside) the fuel tank to the back bottom is broke, if you take it to a Kawasaki dealer and have your dealer call Kawasaki there is a good chance it will get covered as long as the tank is damaged. Those hoses (metal) that run inside the fuel tak sometimes crack, there is really not way of fixing them unless you cut the tank open and then you would need to reweld it.

well you need to find out exactly where it is coming from . tank , line , filler neck , then we can break down the fixing from there .

make sure that all of your little pendulium's that block the gas line when floats are raised are properly aligned in the chamber

you may have a seam leaking on the tank it self, you need to get someone to pressure test the tank for cracks, some kawasakis had recalls on leaking fuel tanks not sure if the meanie was one of them but i know some of the vn1500's drifters i believe had these issues. check with your local dealer or the kawi website about the recall, it might be a seal but most likely a leaking tank seam.