The ama ruling if I am correct for 4-strokes in the 250 class is a 550! I might be wrong. But none of the big companies have been able to get that many cc's out of a 4-stroke motocross bike yet. KTM is getting there. The 520 absolutly ROCKS
There are some weight limit changes coming too. Basically, actual displacement is the hallmark for weight limits, regardless of the number of cams or lack thereof.
Like KX-727 I also heard that the new 4 stroke displacement limit starts in 2003. I'm pretty sure it is 450cc. I thought it started this year, but Dowdy is set to ride a 520 again in the Nationals.
there was a post about the ktm520 and that KTM might be making a 450mxc or what have you. And it said that in 2002 the AMA rules are changing the displacement of all 4-strokes to a max cc amount of 450. Whaw. Things change FAST
I heard from a reasonably reliable source that at least KTM won't stop making big four strokes (I believe the 4-stroke limit in the 500cc GPs is 650 cc). I'm hoping the 520 will go to 540, stock (now available aftermarket).
Smets is a 595cc bike, and Everts YZF was meant to be a 500, but how many people can say they use that power all the time during a race, though u may on a desert race, but if u say u can use that power to the max all the time around every inch of a track u would be in the nationals or world GP's