how loud is this tappin do you think its the oil just wearin in maybe
a while ago i was about to have a whole new set of tappets and lifters the lot due to a hefty tappin noise in the end all it was , was the spark plug loose wich caused it to knock just start it up and see if any ht leads are movin irreegularly i may not have helped at all but its all i can think sorry mate good luck