my 2005 wr450f has recently started blowing smoke and now has low compression when hot. so far my list of new parts includes piston,rings,wrist pin + circlips, timing chain, timing chain tensioner. *this is the first rebuild on the bike as far as i know so should i include a valve job aswell and if not how long will i get before one is needed? (not sure if this means anything but i use 98 octane fuel with valve saver upper cylinder lubricant). also what is the price range for a machine shop too do a valve job? * for the rebuild should i bore the cylinder out to the next size piston + rings or should i just hone the cylinder and install a new standard piston and ring set? * should i go for the standard or high compression piston and ring set? *does anyone sell a genuine Yamaha top end rebuild kit for the 2005 wr450f and what are everyone's experiences with wiseco kits? i have heard that alot of them fail after 10 hours of use. if i think of more questions i will post them as soon as possible. thanks in advance for your input.