help my crankshaft

[zigzag]

hi there im after some help on my 1985 xt600 43f when i take the big plastic plug out of the left hand side genarator casing and grab the nut with pliers there is pull push movement the best i can measrer this is about 0.4 millimeter with verners, there is no up down movement. the bike runs fine and has no bad vibes , there is a noise sometimes when you turn the engine off and the crank is just cumming to rest plus some times when i am kicking it over slowly to find compression to start it but not all the time . the bike has about 23000 miles on it. about 2000 miles ago i removed the clutch casing to check the primary drive nut , this was tight but by pulling and pushing on the crank there was movement although i did not measrer it. in the last 2000 miles its hard to say if it has got worse i bought the bike with 17000 miles on it ,and it had been stood for a few years in a garden , but with fresh petrol in it it started 2nd kick and the oil bled streght away and has run strong since. so how much movement is ok i can find no info in my clamer manual on crank end flote . i know the mains are odd bearings class 3 or c or something could someone give me info on these, sorry this is a long question zigzag