So after a 8+ year hiatus from riding/racing mx, I have decided that I want to get back into the sport and a yammy 4 stroke is the way to go. I've been looking primarily at the used 400s and 426s due to budgetary constraints. My question is: What should I be looking for when I go to check these bikes out? Other then the condition, obvious care that was taken, the routine maintenance schedule and any/all replacement parts/upgrades, what should I be looking for? I'm thinking more along the lines of valve adjustments, cam wear and overall engine condition (I think). Are there any sure signs of problems that may lay ahead? Having ridden 2 smokes exclusively before, I'm kinda new to the 4 stroke thing and I would hate to pick up a bike I think I found a great deal on only to have hundreds of dollars of repairs within a month. Also, I have seen prices vary on the 400s greatly, from all the way down to $1500 up to $3000 - what's the deal here? Is there a such thing as a good deal or am I going to get what I pay for? Any help would be greatly appreciated!