Bought this 1978 SR500 with 11K miles for $2,000 a few years ago, and finally got it running several days ago. All it needed was a tank and carb cleaning to run. And, I replaced the crystalized master cylinder with a cheap Chinese M/C, and I replaced the flasher relay to make it pass inspection.
Came with a tremendous aftermarket Mikuni TM36-69 pumper carb, what I think is a big bore header, and K&N air filter, all of which adds up to awesome.
Hot or cold, it starts exceptionally easy, unlike every XT500 I've ever ridden. CDI-Magneto ignition, with no points to adjust, and the battery has been replaced with a capacitor.
All it needs now is a deep clean and polish, which will probably never happen unless I decide to sell it.
My only two complaints are that it should have come with wire spoke wheels, like some of the European models and the XT/TT500. And, the black color. I wish it had something more along the lines of the 70-73 XS650 color schemes.