4 cylinder 4 stroke. Carbed. Was replaced by the Apex in 06.
Check to make sure the front A-arm & spindle bolts are all tight and bushings aren't wore. That's about the only thing to watch that I know of on the RX-1. I have seen twisted A-arms on that chassis but you can easily just take them off and twist them back.
Then just the basics, check over everything good, make sure it runs right, etc.