Can you spin the valves during valve seal replacement and have them seal?

[scott7556]

My trusty 01 has started to smoke slightly, mostly noticable when I let it warm up in the garage with the door down, I can see the slight smoke as the sun catches the blueish particles in the light. Also when I really hammer on it for a stretch then engine brake.
I ride recreationally and maybe only 10 times a year, but by no means am a full out racer, so before I do a rebuild was wondering if my valve seals might be leaking...

Question:
Can I remove the valves to replace the seals, or do I need to keep them not only in their proper original location, but their proper orientation in the seat? Or if I turn/spin them on the seat are they going to not seal as well then? Also can I replace the seals by filling the cylinder with compressed air so the valves don't fall in the cylinder to avoid removing the head and see if that alone cures my "smoking"...? Am I even on the right track?

[drew416ex]

If it were me, I would go ahead and take the head off and while you have it apart, take the head and valves to a machine shop and have them reseated to make sure they arnt warped or anything. It doesnt cost much, $50 or less. you might also think of getting the next size piston and having it bored becuase the rings are most likely worn also. Those two things will no doubt stop the smoking.

[boosted3g]

Im with drew416ex on this one however if you absolutly know that the piston is in perfect health you can just pull the seals. Take the piston of bdc and start dropping yarn in the cylinder. Take the piston to tcd and you can get the springs off because the yarn will hold the valves in. Compressed air works but this is easier. If done it before in an emergency where i need to race and dont have a spare head gasket.