My son's 2006 TW appears to have broken a valve stem on the intake side as its free flowing and the nut is missing. It runs fine aside from loud tapping which we powered down as soon as noise started. I'm not certain all the steps necessary to remedy this issue and would like to hand him (16) a repair manual and buy him the parts he needs. He has replaced his instrument cluster in his tacoma so he is somewhat techie....is this a 16 yr old project? Bike has 3200 miles.