I have seen honda's with power valve's, George Jobe had one. And Stefan Everts rode it 10 years later or so at Namur in his 250 frame.
Really...well I wasn't aware of that. I'd sure like to have a look at one of them.
Kaw rider, this isn't an argument, or even up for debate. A person doesn't need scales to feel the difference. An '01 CR crank is a 1/3 the weight of an '89 KX (and lesser still than late model KX's). I don't know where you miss read that at, or who tricked you into thinking otherwise. My postal scales don't lie or leave anything up for interpretation.
there is a reason why both motors don't have the same power delivery.
Yes the KX's power valve has much to do with it's broad torquey delivery of power.
Like I said this isn't an argument. You can post why you think the CR crank is heavier and that's fine. I probably won't say otherwise. I provided legit information as to the comparison of an '01 CR and '89 KX. If I put both cranks on the scales and posted a picture somebody is still bound to disbelieve.