Need Help with Topend!

[Sick Twin]

hey guys i could really use some advise here. My bike just started knocking (sounds kinda like a lifter tapping on a car).and it did seem to go up and down with motor. i pulled the jugs off to check for slop .And what i found was that i could spin the pistons a little each way on the rod.now i know this is odd but they are both doing it about the same distance.I brought each piston up to top dead center to check for play in the crank . i had no up and down movement on the rod but just a little side to side as normal but felt tight.I checked the flywheel to see if it was trashed but seemed to be tight too. so now i sit here with this banshee motor on my pc desk lol! and still have no clue.. if anyone could help me with this i would really appreciate it even if u just have some ideas really hate to go throught the bottom end if i dont have too. thanx again for the help guys

[MotulMonsta]

you can spin the pistons along it's yaw axis(verical)? You got shot bearings in there. You'll get a little movement but it shouldn't be alot. Now remember the rods use roller bearings on both ends and they slide left to right along the crank and wrist pin..that play is allowed. but up and down motion is a no go. It won't cost you much to put new wrist pin bearings in there..hell buy a kit for 40 bucks it'll have rings, bearings and new wristpins and clips. The lower rod bearings are going to be the bitch. You got to split the crank for that...It's cheaper to buy a complete crank from wiseco then to split a stock crank.