I just got a 2001 xl sporster and notice that it make noise like if oil pressure was low but the oil light works fine. I open the valve cover and check the rocker and push rods and they look o.k. also removed the cam and I do not know if they are stock or after market I need help this are the numbers on the cams. front cylinder; ex. 15-1 24856 in. 15-3 24857 rear cylinder; ex. 15-1 24856 in. 15-2 24861 I read that if you replace the cam alot times the top end noise is more noticeable. is it true.