Originally Posted by SJktmRider
Hey guys.. Curious how many hours everyone has and how well the valves, cam and rocker arms are holding up on the 500s. Im still curious how many hours people are really pushing the top ends on these bikes.. and hopefully no grenades
Exactly the same top end as the 530's. They held up great if you kept after the air filter and didn't have an early 08 version with weak rings. I've seen one run for 60 miles in a race with no oil. It only needed on rocker and the plastic chain guides replaced. The valve train is all on roller or ball bearings, no slippers, no plain aluminum bearings.
Keep after the air filter. A tiny amount of dirt will effect the intake valves and they'll tighten up. More dirt or sand will get the rings/piston/bore. Get two filters and swap them out frequently. The original TwinAir is better than the NoToil. The Motorex oil is much better than NoToil also. TwinAir has an extra/optional dust filter that works for dusty or long rides. ALWAYS check around the sealing surface to absolutely MAKE SURE you have it installed correctly. It will fit perfectly or it will have a gap big enough to stick your hand in. I'd expect this topend to go over 20k miles with good filter replacement.
A friend has a 2012 500 exc with 7500 miles, mostly two track and pavement. It runs better than mine with 2000 miles.