DR Brush mower starter cranks but won't engage to turn engine

I went to start my 14.5HP DR Brush mower for the first time of the season and the starter cranks but the gear on it doesn't rise up and engage the big gear to crank the engine. It moves up and down easily when I grab it. When I crank the starter it spins but doesn't rise. When I let go of the key it then pops up a little, but not high enough to engage the gear. If I hold the starter gear up and crank the starter it doesn't rotate when the starter motor is cranking. It worked fine last season when I put it away. Anyone have an idea?