I'd fill the carb bowl with (fresh) gas & run the pump inlet into a can of (fresh) gas & cap the carb nipple & I would preoil it after all this time & oil the cyls. I'm assuming it ran when parked so I would disable the starter (pull the yellow wire at the starter relay) & see if your connections are correct & everything is being fed in "crank" & "run" that should be. I'm assuming the dist has been moved so confirm basic timeing (15 BTDC is good)