i purchesed a used lawn tracter mtd12/36 with a separate snowblower. i dropped the mower deck,have connected everything for the blower. it ran well. i shut it off,lowered the blade engagement lever one more time to check it befor i put it away, the snowblower wouldnt engage.the lawn tracter is mod#139-612-000 c149b. the blower is model#190-491-000 io17d.