I'm doing a basic top end rebuild on an Xplorer 400 (2 stroke). I bought it "not running" and knowing it needed a new top end. As I removed the header pipe from the head it had sitting water in it. After removing the piston I noticed the ower connecting rod doesn't move too freely, it's not siezed up. Seems like the needle bearing may have a little rust due to some moisture and sitting for some time.
There is although no play as in side to side motion so it shows no sign of your typical bad bearing senerio.
Should I give it some type of lube to help free it up and continue with the rebuild or is the something that is gonna to require splitting the bottom end?...which I have never done.

 

If there is any binding at all in the bearings they need to be replaced. I would also replace the crank bearings and seals at the same time.