You can turn the WR cam one tooth over to have YZ timing, so there's no use getting YZ cams. Hotcams have various grinds that get more agressive so if you're looking for more power you're looking for aftermarket cams.
Other power options:
ram air (not very effective below 90 MPH)
high compression piston
high compression piston with alcohol fuel
high compression piston with nitromenthane
That's all I can think of
ok. some of that sounds a bit to far and more on the drag racing side. lol
just some thing i was wondering about. do they have any aftermarket CDI setups for them?
and what is a good site to check out hotcams?
"I remember reading an article about year model differences in the 450's. There was some kind of problem on the first year 450 which was corrected the following year, but I have no idea what it was."
That was the first year 450 in 03. They had a issue with the woodruff key in the E-Start.
Do not forget the benefits of e-start, that alone is enough the go to a 450 over a 400/426.
"then i started thinking they had to of changed stuff and would the changes be better or not?"
I think it's safe to say, newer is always better performance wise in the MX world, with some small exceptions of first year products, etc, but they are always improving things like suspension, handling, etc. The WR has been the same basic engine for years now, with some changes in exhaust, cam's, timing...etc. which makes almost no difference if you change exhaust and cam's, etc. Also remember they went from steel frame to aluminium in 06 or 07.
Of course, if you simply want brute power, you can always shop for a CR or KX 500 2 stroke too....lol
so i know to stay away from the 03 450s.
i don't know about E start yet tho i mite get to lazy not kicking it over all the time. lol but then agan my kicking foot has been broke since the last time i had to kick over a bike. (500lbs of 4 wheels will not do what a bike will opps)
i think a 2 stroke would be some thing i would have as a back up bike. i mean who don't love a screeming 2 stroke lol.
are the aluminium frames just as strong?
i just picked up an old 85 RM250 last week dirt cheap and within 3 days i have a 6" chunk of frame broke out. (opps agan lol )
you guys are very helpfull thanks a bunch
keep the info coming.