Ah i see. Right well heres the story like it is sorry to say

If the engine is tapping, then yes chances are the hydraulic lifters (tappets) are worn, but unfortunately on a CVH engine the only way to cure the problem is a new cam and a set of lifters. The cam wears and later in life wears the lifters out, putting a new set in will last for a few minutes before it taps again.