need advice 2001 cr 125

How tight to torque rear axle nut? I removed the wheel to work on the brakes and remove a link from the chain and now when i torque the rear axle tight the wheel is almost impossible to turn by hand, i assume i am over tighting but i am barely tighting enough for the swing arm to close (you know how it spreads apart when you take it apart?). I hope this makes sense. If i tighten to where the wheel will still spin it doesnt hardly seem tight enough. What gives? Its been awhile since i worked on a bike....

The spacers are there, i do not know if they are different lenghths or not but i made sure to remove them one at a time and put them back one at a time so as not to get them mixed up.
What i truly believe the problem to be is me. I thought the chain was to loose, i could pull it almost off of the rear sprocket at the rear center (not the top). The chain adjusters were already cranked almost all the way out, next to the last notch. So i removed a link and now i have the chain adjusters cranked all the way in which works good and there is plenty of slack in the chain..... until.... i go to tighten the axle, and then for some reason the chain gets real tight and the wheel is hard to turn.....
I cant seem to hold the wheel all the way forward and crank the axle down and it stay there.... its frustrating....

Actually i got it figured out and everything is "a" ok....
I didnt have the brake caliper mount in the slide correctly so when i was torqing the axle tight it was putting the brake rotor in a bind... i took it all apart and took my time putting it back together and everything is perfect now....
but thanks for the input as i do have a new chain and sprocket set on the way....