I have a 1995 Sportster 1200 with 16,000 miles on her. The oil is changed every spring and she is severely pampered. I started her up today and immediately heard tappets slapping. The oil pressure idiot light came on for the first time ever. I let her idle for about a minute thinking that the oil pump had lost it´s prime, but no luck. I slightly rapped the throttle a couple times, and let her idle for another couple of minutes, but still no change. Anyone else experience this? She ran fine the last time out...