I recently acquired a D2 serial number 5U707. I was able to load it, bring it home, unload it, and park it two weeks ago with no issue. Now when I try to start it, it seems the pinion is engaged, but when I push the starter lever forward, the diesel doesn't start turning, and you can hear the load on the pony motor. I'm wondering of the pinion clutch isn't engaging enough and needs adjustment, but not sure. Also, IS there a way to adjust it?