What's the easiest way to check the chain? I mean, I can see why it would be broken, I rode it, and it was firing up.

Yea, I also disconnected one of the vent tubes that go directly in the carbs, didn't help.

Bowls are full, when i unscrew the drain scew from the float bowl it flows gas, all 4 bowls.

I almost want to remove the air filter and cover and shoot some ignition fluid into the carbs and see if it fires up that way

 

ok so I sprayed ingintion fluid into the carbs and the bike hesitated but did in deed fire up... I drained the gas from the pump and it was orangeish (diluted rust color) but it was coming clean colored from the tank... weird..

 

what does the fuel filter look like on the bike? clogged with grime? If the gunk made it into your new fuel pump chances are the carbs are gunked up now also. time to take them back off and check them. While you have the tank off id clean it out along with replacing the filter and cleaning/replacing whatever fuel lines are bad