Motorcycle Repair: 1999 EVO rattle, stethascope, luck mike

Question
1999 EVO, running points, S&S super E carb,in custom built bike, 8000 miles on it. I have a rattle or knock in the motor. Have used mechanics stethascope and found no noise in lower end,lifter blocks,cam,cylinders,primary case or rocker box's. Hear a loud knock from carb but assume it's due to manafold openings on valves. Knock seemed to go away with increased RPM's, suspected top end oil starve, incresed oil pressure with new relief spring. no help. Bad gas knock at idle? or rocker arms? motor runs fine and strong, but knock seems to be getting worse.

Answer
Generally, a knock that goes away as the RPMs increases and then comes back when the bike idles is a rod.
I would start by removing the primary cover and make sure you dont have a motor sprocket nut loose or a trans pully loose. Then go to the top end and start tearing it down, inspecting each part as you go.
Good luck
Mike