I had a '70 CT-1 and a '73 CT-3 and the things I had to figure out with help (and a manual) were how the oil injection works and the carb needle deal.
There's a wobble-plate pump and when the engine is running, oil is slowly pumped in. When you open the throttle, you increase the excursion of the wobble plate, and oil is pumped in faster. It's a clever design, and all goes on under the right-side engine cover.
The carbuertor should be cleaned and inspected, and the needle that hangs down in the middle of the sliding sleeve deal has three positions - this controls mid-range mixture. I think there are either jets or screws for idle and wide-open throttle. If any of these are plugged, you'll get a bike that either won't run wide open or won't idle.
Neither of my bikes were fast, but when you drive an FJ40, anything you can wind up to 6000 rpm is fun. If they smoke a lot under throttle, you can back off the oil a bit on the pump adjuster - they shouldn't look like a mosquito fogger. If you suspect the entire auto-oiling thing is messed up, you can premix oil and gas and just put that in the tank. HAving said that, if there is no blue smoke at all, you could be running the bike with no oil, and that is badness.
My '70 had electric start, and like most bikes of that era, the battery charging by the combined starter/alternator was weak, and even a new battery had trouble starting the bike.
One of my bikes only had 1200 miles and looked like new - it was very sharp after I resto'ed it. Have fun - these bikes are a good low-cost way to expand your gearhead skills.
