Change it back to 250=250 , Open=Open.
You would be suprised at how close a 250 2 stroke and a 250F is in lap times with a Pro onboard.
Both bikes have their + & - at different tracks.
As usual, I am here to agree with you. I have been looking at lap times for a few years now for unrelated reasons (I promote my own series and it helps me in designing safe tracks) and you are right; "A Pro rider will turn very similar lap times regardless of the bike (correctly set up)." Now I can't say he can do that for 45+2 (or even today's 30+2) but for most of the moto, he will turn the same lap times. It is one of the reasons I prefer "Open" classes ('run what you brung').
In the 90's I moved off the open class bikes and into the 125 class because over the course of the race, I was faster on the 125 (fitness played a big part in it!). Holding onto a 500cc monster for 3+ hours was getting to me and the 125 made racing fun again. I was still whipped at the end but I was still pushing rather than wheezing.
The thing is, I'd bet Mitch (et al) could make a 250 2T make equal HP to the 450 4$ but would it be ridable? And if you did, would it not be a hand grenade just link the 4$? And would it not be just as expensive or filled with unobtanium preventing the privateer from competing anyway? And is that the direction the AMA and FIM want to take the sport?
The problem as I see it is that what wins on Sunday, sells on Monday. Of course the average rider, the 80% of all bikes sold, is not a professional racer and would be better off on a KDX200, but the buying public wants what Ricky/Bubba/Chad/and Ryan have. They spend millions on Rockstar/RedBull/Makita sticker kits to make their bikes look just like the pros. They buy exact replica riding gear. Count the number of Monster helmets you see at the next local MX. I am willing to be they are not getting one dime in return from Monster! And since Jeff Fredette isn't kicking everyone's ass on the KDX, those are not selling like hot cakes. The manufacturers traded off having THEIR bikes costing $40k and selling to the public cheap knockoffs for $2500 to having EVERYONE pay $10k. Yet to be competitive, you still have to invest another $30k+.
At least with the works bikes, the rest of us could afford to have a good time.