valve stem seals

When is it time for new valve stem seals ? Do they have to be changed when the valves are reseated or can the valves just go back in whith the old seals?

K-Man...for as cheap as they are,You'd be a Fool if You didn't replace them now,while You have it all apart,Bud...for SURE!
That is,assuming that You either HAVE it apart,or You PLAN on having it apart.
You can get the seals from Jeff @Z1 enterprises.
You should also take a close look at the guides(and other things) while You have it off too...check for excessive play,etc.
The head plays such a vital role in the performance of Your engine,and You'll kick Yer butt if You assume. :ohmy: :whistle:

There doesnt seem to be much play at all between the stems and the guides so I think the guides are ok. Do the seals just pop out or is there some sort of procedure to replaceing them?

the seals ,if they are the metal cased ones, can come off with a pair of pilers, to put them back on, is the metal ones, need a tool to do it, if they are rubber then they just silde on, just make sure you have oil on the valve stems when you assemble

You'll more than likely tear them when You try to take them off.They may be dried and brittle.
Just My opinion,Bud,but like I said...I would just order new ones for peace of mind.
You MIGHT get lucky and get them off,and back on again,with no damage,but You WILL kick Your ass when the bike smokes on start-up,next season...:whistle: ...:laugh:

Sweet, they are the rubber ones, I guess I will go ahead and change them out. Thanks.

Glad to hear it,K-man.

Where do plan on getting them from?
Do You have a local supplier that might be able to get them?
If You only need the seals,then check with "Parts-Canada" at any bike shop,and see if They can get them for You,or like I said,You can get them here...

www.z1enterprises.com/detail.aspx?ID=101

but it probably wouldn't be worth it,to get them from the U.S. if that's all You're going to need,if You know what I mean.
Jeff(Z1 ent.) has a LOT of available parts,and the shipping IS amazing(fast)...just so You know.