I had planned on getting an '06 450 but the fact a really need a green sticker bike is forcing me to look at the '02s. Currently I have a CR250 and I have always had 2 strokes so please forgive my ignorance..I am trying to change my ways. If I bought a '02 I would probably want to replace piston, rings, and bearings. I am assuming these parts cost about the same as a 2-stroke? If I by a bike and the tranny goes out(I have read a number of post about 426 issues about loosing gears) what type of repair bill would I be looking at? Also what are the maintenance costs on the valve train and is there anything I should have replace while I am doing the piston and rings? Last question: Will the exhaust actually burn through my riding pants if they are "over the boot" pants? A friend of mine has the Yamaha 450 quad and said the thermal header wrap doesn't work and he can't wear over the boot style pants. Sorry for the long post but I appreciate any positive responses.