[bowser]

Just picked up a 2010 which has 70hrs on it, still is completely stock and currently runs fine (original piston, clutch etc)

about to fit some goodies to it and build it into more of a woods bike rather than a track bike
- akrapovic system
- TB insert
- Air4orce intake
- ECU flash

I see some guys replace the piston around 30hrs
deciding if I should do a top end rebuild/cam install or bottom end as well?

[riddler9]

if the bike was raced on a regular basis then the piston needs to be replaced for sure. If you are doing the piston, take care of the timing chain and sliders. Consider doing them regardless.

Check the valves, likely fine for another 50 hours but you need to know.

Check the clutch. Replace anything that is not in spec.

Replace the fuel filter, clean or have the injector cleaned.

Clean and grease the stem bearings.

Clean and grease the hubs.

Clean and grease the rear linkage and swingarm.

Check the torque on everything including the motor.

Consider changing the fork oil. Replace the seals and bushing if you do.

Torque the spokes.

Chain, sprockets, and tires depending on wear.

Leave the bottom end as-is unless you have reason to suspect a problem.

Ride the piss out of it.

[bowser]

One of the intakes is way out of spec (0.05mm), the rest are fine.
Will leave the bottom end at this stage and just do the valves, chain guides and hotcam 2

[crfsonly]

once an intake valve tightens you have no choice but to do a valve job and get new valves. we have a full offering if you need a source for this service and parts.

i would inspect the guides and replace if needed. the cam chain is cheap insurance and recommended. check your piston for spec.

ken