The motorcycle will run in the on position of the petcock....but will die as if it ran out of gas...gas tank full...I switch the petcock to reserve..n run great ....it started after I change an aftermarket muffler to the og. One.......

It's the fuel petcock switch. Here are some pictures of it: https://www.google.ca/search?q=2004+kawasaki+vulcan+1500+fuel+petcock

Fuel petcock valves are common on motorcycles which don't have a dedicated fuel level gauge. They are use to turn the fuel tank "on" or "off", and they also have a "reserve" position which taps into a section of the fuel tank which contains reserve fuel to allow you to make it back to a gas station should you run out of fuel in the "on" position.

Sounds like the reserve lever on the petcock is not being used, Your petcock should have 3 positions, OFF , ON , RESERVE. Learn how to operate it!!
Reserve will allow you to run a few more miles to get to a gas station!!

Tube inside of tank has a hole in it.

If you look closely at the petcock, you will see ON and RES printed on the ring around the petcock and an arrow on the lever. Point the arrow at the position you want. Otherwise, you'll have to take the petcock out and determine which is which. The petcock will have screen with a tube in it. When the lever is in a postition where air blown through hose nipple comes out of the tube, this is the "ON" position. When the fuel comes below the top of the tube, the engine runs out of fuel and you have to switch the lever so that fuel is taken in from the lower inlet.

Good Luck
Steve

With the age of your machine , you should drain the tank and remove the petcock. If you can take it apart rebuild it. If you have no reserve , either the reserve tube is broken off or the petcock is plugged. It is possible the four hole washer the seals the the lever and diverts the fuel is damaged , worn , or broken. Depending on the over all condition of the petcock replacement of the entire unit may be the best option. At any rate an new fuel petcock would definitely fix this issue. Rebuilding your old petcock is only an option if all the parts you need for it are available.

Try tapping on your fuel pump with a plastic hammer with the ignition switched on. Or bypassing the fuel pump completely with a piece of fuel line. It sounds like you ran out of gas which is related to the fuel petcock position or a non-functioning fuel pump.

Make sure you've covered the basics: fuel petcock should be in the "on" position; ignition must be in "on" position; kill switch must be in the "run" position; bike should be in neutral. Make sure there's fresh gas in the tank. Check the oil through the sight glass on the right side of the engine, with the motorcycle balanced and level. Check the spark by taking out the plug and holding against the engine while you crank the starter. There should be a blue spark that appears with every second revolution of the engine. Check the gas flow by pulling the gas tube off the carb and turning on the petcock under the gas tank. Gas should flow freely from the tube. If all of these tests check out okay, you may have a carburetor problem, such as a plugged jet. This is quite common if the bike hasn't been used for some time. Removing the carb and cleaning it isn't overly daunting. Check the TW200 forum at http://tw200forum.com/. There's lots of info there. Also, download a copy of the shop manual. Good luck.

Do you have a petcock on the bottom of the gas tank? If so, if you have a "reserve" the petcock will have three positions, off, regular and reserve. If you only have a two position petcock you have no reserve function. Petcocks work by taking the gas in the petcock tube higher up in the gas level, once the gas level drop below a certain level on the gas tank pickup tube, the petcock has to be switched to reserve where the tube picks up gas at a lower level. Hope this is not too confusing.

On the later model bikes that have carburetors, the petcock is vacuum operated. You must turn the engine over until the float bowl fills up enough for the engine to run. Some petcocks have a "prime" position on them but I don't think the Harley does. That's one reason I suggest that owners go to a high quality manually operated petcock.

Now, this brings up the question,"are you sure you ran out of gas" or did your vacuum operated petcock go bad on you? This is what they do. I've seen guys with nearly a whole tank of fuel "out of gas" because none was going into the carburetor. The vacuum operated petcocks are notorious for this. One one occasion, I saw one leaking air so badly that the bike nearly would not run. They are source of trouble that will show up at the most inopertune time. My advice, change it and buy a Pingel petcock. First class part and they ain't cheap but worth every penny. Good Luck, Steve

When you switch to the Reserve position, fuel is drawn from the bottom of the tank (vs. from a tube sticking up about 2" from the bottom, when in the On position). Something is either blocking the flow of fuel into the Reserve inlet on the petcock, or the rubber seal inside the petcock is coming apart and blocking the flow of fuel. Either way, drain all of the gasoline from the tank and remove the petcock so you can see what's going on in there.