could piston rings be worn even if they don't look like it?

[elephant35e]

ok, so awhile ago i did a compression check properly, thorttle wide open, engine warm, and kicked it pretty hard and it read 92 psi. i heard 125cc 2 strokes needed 160 - 180 so i figured out i needed new rings. well i took the head off and it looks like the rings aren't really worn. could they be worn even thought they don't look like it? or could other things cause low compression? if so, what? the o-rings on the head didn't look worn either.

if ths helps, its a 2002 yz125.

 

[ellandoh]

if you have it apart change the rings whether they need it or not, measure the piston and maybe get a whole top end kit. check the condition of your reeds, and clean your powervalves if your bike has them.

rings are probably 10$

 

[BSWIFT]

For under $200 you can do the whole top end. You'll resolve many issues this way. 125's tend to go thru rings and top ends fairly quickly, nature of the beast. Definitely change the rings since you are already in there. Clean your powervalve and carb. You'll be happy with the results.