i still cannot work it out,the cylinder is ok checked everthing out on it and it is spot on. before i took the cylinder head off to rebuild my engine it was perfect now up to 2000 revs it makes a clicking sound,it sounds like it is only one clicking,when it goes past 2000 it goes and the engine sounds brilliant , what else do you think could make this sound because its so annoying,an when you rev it up standing still its perfect thats why i dont think its the tappets any ideas please