I also picked up this massive POS 82 XJ650 G50 yesterday for a build/restore. It doesn't run at the moment, previous owner claims it needs carb work, which it does. I already know the issue; XJ's come with pretty much a maxed out tune from the factory. This bike is straight header (will be adding mufflers later tonight) and also quad pod filters. These cause it to run lean and the carb does not get enough vaccum to pull up the floats without there being an airbox. I ordered a stock airbox to make a custom intake/box. Other than that it is pretty much bare bones vintage style. More details to come. I love this thing.