HI, i have just purchase a 1990 xr2i with 38,000 miles on the clock and the mots and service history etc to prove it. the problem i have is that the engine seems to tap its little head off especialy when you get above around 3500rpm. Now i know cvh are always tappy but have never had one anything like this. Previous owner says he has fitted a piper cam kit could he have not correctly ajusted the tappets? any other ideas?