These machines are as sturdy and durable as a brick, with minimum maintenance. Most of them are just neglected to death. Remember that in 1984 there was no synthetic oil, and they used regular gas. So, clean it up, check that the rollers in the variator aren't totally flat, check the condition of the belt, make sure your tires aren't 25 years old, and enjoy! There is a 150 service manual at http://www.hondaspree.net/phpBB3/vie...hp?f=11&t=8558
Sometimes the rear bearing in the swingarm is bad, but it could be dry. The bolt holding the rear wheel rotates with the wheel, but it can be loose sometimes. Most times the speedo cable is broken inside, but you can still get them from Honda.
The 85 150 is the same machine, Honda just increased the displacement to get it to meet standards for freeway legal.
These are very ugly, but they are the best scooters ever. They just run and run.