History: The 446 first appeared in 1972 and disappeared in 1989. It has a 16 HP Onan opposed twin cylinder air-cooled engine. It is driven hydraulically. It weighs around 800 LBS by itself. All of them were well-made tractors but improvements were made to them over that 17 year run.tjl5709 said:Found one online. Curious about the history of these. Things to look out for? It's very well maintained with allot of attachments that I currently can use. Any rough ideas on market value?