I have an 05 YFZ that I installed a GYTR hour meter on when bike was new, I have 150hrs on it now. I had the yz cam mod done at 20hrs, and valve clearence checked at that time. I just had the valves reshimmed at 150hrs, and the mechanic that I took the bike too claims that 150 hrs is a LOT of time. The bike still runs great without any unusual engine noises. My question is how many hours are some of you folks getting out of your YFZ before anything major needs to be done? The mechanic says that rods tend to break, pistons tend to go sideways, and valves break after a lot of hours, I don't quite buy this, but what have you guys/gals experienced? Thanks for any replies to this thread.[img]i/expressions/face-icon-small-smile.gif[/img]

Cam mod
48 pilot 175 main
full Yosh TRS
Pro-Flow K&N
other than that stock, entirely sand dune riding.

 

When i had mine, one dealer said 60 hours another one said until you notice a performance loss. So go with your gut on it.

 

I can't comment on how many hours you should get between rebuilds, but you can't treat it like a 400EX either. You are riding something that revs out quick and has a 10,750 RPM redline. Personally, I would rather go through it BEFORE a problem comes up. I too have heard a lot of differing opinions on the matter though. Personally, I would think you are OK for a while unless you routinely race her and ride as hard as you can.