I could use some help/advise on how to proceed.
'99 GS500EX
I was adjusting valve clearances and noticed that my intake camshaft has a spacer (shim) on one side (near the side wall of the head) and the exhaust camshaft does not have this spacer (shim). I also noticed that the intake camshaft moves laterally quite a bit less than the exhaust one when I push on it with my hand (perhaps 1 mm).  I beleive there shoudl be a spacer on each camshaft to take up this end play.  Just how critical is that spacer?  The bike runs well which may not mean much in this case.
What do you think?  Do I need to replace this spacer right away or not worry about it?  I already put the bike back together so I woudl have to tear down again if needed.
Thanks in advance.

Its not super critical, and you will hear a "tinking" noise when you come to a stop due to the side play. Its a common problem with the GS. It doesn't hurt the engine at all, its just annoying to hear.

My 99' GS has one washer on the intake and no washers on the exhaust as well.

Thanks for the info - that's about what I thought.

Anybody else want to add their 2 cents?

1mm play is huge. The shims are 1mm, 1.1 mm and 1.2 mm only. If you have .3mm you cannot stuff a shim in it, and it will only clunk enough to annoy the crap out of you 30% of the time.
.5mm and its louder and you hear it 50% ...
My 89 had one at .5mm, and one at nearly .1mm. At 45K miles I took the .5 cap off and put material on its side. Then ground it back down. Bingo. Whisper quiet at 45K miles.
Cool.
Buddha.

Thanks Buddha - maybe next time I am in there I will measure and buy a shim and modify the thickness if needed.
I don't notice a lot of noise but maybe I just don't know what to listen for - or maybe I'm a little hard of hearing!