Pistons - Sleeves - Valves

[Longer]

So I have the head, block, and pistons off.

Everything looks pretty good, all the sleeves and pistons are smooth, no gouges or abrasion.

Questions

Is all the carbon buildup on the piston heads and valves a standard "look" for an 85xxxkm engine?
Do I replace the sleeves and pistons even though everything looks great?
Do I replace the cam exhaust chain?
Do I replace all the valves and components?

I'm thinking that the block, sleeves and pistons are good, but will replace the cam chains and valve assemblies.

 

[amc49]

The carbon is normal. Looks mean nothing if the parts are out of the tolerance ranges. The rings at least will be pretty worn and really need replacing but the cylinder holes can be honed only if you find some standard size rings. You check for cylinder wear by carefully removing the carbon ring at the top of each cylinder and then check how much cylinder wear at the top where the carbon covered it up. The max normal wear point is often right at the bottom of the top carbon ring. The pistons can be worn and still look smooth as well.

The smoothness of engine parts often is an indicator of low wear but not necessarily, they can easily be 'smooth' worn out.

 

[Longer]

Excellent - Great advice thank you - I’ll get into the measuring then!

How about the valve assembly etc? I’m assuming it’s something to replace.