Mont, I assume Asasin in his first post was talking about 250 four bangers, as on average they make 36hp. But I do agree with you to some degree, you say the 80's bikes! I say it wasn't until the 1982 YZ250J, the 1st of the mighty power valve by Yamaha (YPVS) the engines became smoother more user friendly & tractable. I also agree that towards & around the years 2000 that some (not all) of the bikes were very powerful, explosive & harder to ride than the mid 80's bikes. In fact some of them were producing close to 50hp at that time. I have both YZ250 & KX250 2001 models. Both bikes are stock & all I can say is the KX screams it head off up top & is much harder to ride! The YZ has a much stronger bottom end & mid & is once again smoother much more tractable & user friendly.
Cheers
Ando