My 93 EVO motor really taps at 2000 rpm. Very noticable. I tried to check oil screen in timing case but can't get the plug to budge. Any suggestions out there? Special tool?
You might want to try replacing the ball & spring on your oil pump check valve. If it is weak and leaking you might not be getting enough oil pressure. Also, If you are running a HD 10 micron oil filter that can restrict oil flow as well.
I was going to try the hand impact tool next but was unsure how much hammering the case can take without damaging. Are these plugs usually this hard to remove?