Recently I noticed my 1500 appears to be slipping the clutch?? A couple of days ago I was riding hard, engine running about 3250 rpm in OD, and without changing my throttle postion the engine would rev up to 4000 and back down but my ground speed would not change. I had also noticed that while riding in 4th and if I would get on it hard , the clutch would appear to slip. Has anyone else experienced this?