Hears my problem. I bought my 08yz450f in Feb of 08. Since then I have raced all the gncc's in 08, several this year, most sera hs, and a bunch of other local mx and enduros plus a 24hr race. Well over 100hrs.In Nov I am doing the Baja 1000 so it is now time for a rebuild. Up to this point I have adjusted the valves once. I know I will need a top end, valves piston etc.Parts cost $500. This is my issue. I am going to guess that when I pull it apart the cylinder will look pretty good and the bottom end will feel ok to. But, considering the hours and the upcoming Baja should I spend another $500 and replace the bottom end, main bearings and cylinder just to cover my bases? I think I know the answer but I guess I am looking for a little push.