The bike is currently not running, but the motor turns over easily.
Keep in mind that the bike has been sitting for 3 years before the previous owner decided that he no longer wanted to store it and started throwing money at it trying to get it to start.
He bought a new battery, got the tank cleaned and coated, and had the carbs done. All by the same bike shop. 3 years ago, he also bought new tires and had them put on by I believe the same shop, I can check my records on that one (he kept all of the receipts

).
The battery that is in the bike is only a few months old and supposedly holds a charge when not attached to the bike. I have a spare battery from the XJ600 that I attached to the GS750 for a while trying to figure out if I could easily start it and kicked it over a few times.
The previous owner, in all his police officer wisdom

decided that he should try to fix her up. So, he pulled the tank off and removed something. He replaced that something that he removed with two inline fuel filters and new fuel lines for the and I quote, "the main fuel line and the reserve fuel line." I removed the reserve fuel line he added and replaced it with a vacuum line. I added some vacuum to the line and the petcock pulled fuel into the line and it looks like it passed through the fuel filter just fine.
The tank was empty and I had a gallon of gas laying around that was a week old. So, I added the gas and tried kicking it over a few more times. No luck still.
Just to make sure it was not the battery giving trouble, I hooked it up to my car and started her up, 13.6 volts on the dot constantly.
So, I going to check over a few more things soon, but if anyone has some advice on these old girls, it will all be appreciated. I will be pulling the spark plugs and checking them when I get some more free time.
P.S. She drained the battery from the XJ600 pretty quickly as after half an hour to an hour of it being plugged in and the ignition on, it was down to 8 volts. I also found out that every time I kick her over, she gains 0.05 volts. Also the starter does not work, I am not sure for what reason, but if the system can handle it, I want to remove the starter, starter solenoid, that part of the harness, the battery, and replace it with the proper capacitor and make her kick only.