We just had our local clubs swap meet last week and there were a ton of four strokes new in box for sale and even more used engines. All brands. I picked up a parts engine, a YS 91 for 20 bucks and when I got it home all it needs is a new rear bearing. I will install all new bearings and a new ring but there were a lot of engines to choose from.
Because we had a Saito dealer in my town there were a lot of them on the tables for some very good prices. I love swap meets.