Hello All, I have a problem I cant figure out. I have little to no oil pressure after the engine is warmed up. At start up I have about 30 psi at the oil pump and at rev I have up to 60 psi. Once I ride it about 3-4 miles its drops off and then the clattering starts. I have replaced the oil to 70W and I also replaced the side oil pump spring to a stiffer spring. I cleaned out the tappet screen and replaced the oil filter too. I installed a reducer on the up tube to the rear head with a .063 jet. I have not had the oil pump off nor have I gone into the cam cover or any of the tappets. This is a new problem to me but so is this bike. Any and all help would be greatly appreciated. Thank you.