I have an 89 Sportster 1200 that had been sitting for approx. 3 years that I just started riding a week ago. This morning when I was driving home, I squeezed the clutch in to rev the engine while approaching a busy intersection and when I let go of the clutch, the bike never went back into gear. I can feel the clicks on the shift lever, however the rear wheel won't engage. The spring is fine, I adjusted the clutch, and changed the gear oil before I started riding. Any thoughts?