Needing some help on an ATC

[zRxsix3]

Alright last night i helped a buddy of mine pick up a 200x with a 185 engine for 200 bucks, she ran and drove after throwing an inner tube in it. Well while riding we noticed it smoked, it first only smoked after you would rev it up and a puff of blue smoke (oil) came out the tail pipe. We rode it for awhile and some hard riding it seemed to smoke a little more, he is talking about a whole rebuild but i am thinking he needs to check a few things like valve clearence or top end before making that commitment, so some one with expertise comment about what we could check! Thanks!

[DohcBikes]

This might sound dumb but did you check, the oil? Could be over full.

Does it have good power? Does it run good?

I also now it may sound insane to some here, but you could get crazy and do a compression test.

[zRxsix3]

I did check the oil and none of those things sound dumb or insane... it does run good, although going down the street it seemed a little funny like it was cut to g out but i only rode it the one time...ill try the compression check! Thanks
any more advice would be great