I have 3 of them and have never checked it on any of them, but I can tell you that Augusto told me that in south America , they come with 2 different head gaskets, 1 for sea level and the other for high altitude. personally I found that any c.c.'s less than 11.6 to 12.0 it is very easy to stick them here in central Fl. I totally agree with Al on the subject, but just never got around to it. I did however check my KT's yrs. back and found that he's correct.