03 Yz 125 top end problem

Blew my bike up then i got the cylinder nikielsealed , bought brand new piston and rings with gasket kit.

Put everything together to spec and started her up and she sound beautiful until a little rattling noise in top end area, after i would rev her up it would do it on the way back down. 

So i took her apart the cylinder is fine, but the top of the piston is &%$#@!ed along with the head.

What could this possibly be from?

the power valves look fine


2014-03-22 14.17.11.jpg2014-03-22 14.17.16.jpg2014-03-22 14.17.20.jpg2014-03-22 14.17.28.jpg2014-03-22 14.19.03.jpg2014-03-22 14.19.06.jpg2014-03-22 14.19.10.jpg2014-03-22 14.19.17.jpg2014-03-22 14.19.33.jpg2014-03-22 14.19.50.jpg

Pull the cylinder block of and check the play in the connecting rod on the cranks shaft. If there is up and down it needs tp be replaced, side to side is fine.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Similar Content

    • By Rick Mcqueen Art
      A tiny clear rubber tube on bottom of carb.  On bottom sort of on side, by floats, the other end just hanging down.  Was it always like this? Or does the other end go somewhere?  Today after multiple trys with kick, choke on/off ,,,fuel keeps pouring out the tube.  This bike has always been hard to start.   Thanx  guys!
    • By Brock granberg
      I just did my valve adjustments and put my YZ250f back together as far as the valves, shims buckets and cam covers on but I need adhesive for the plastic valve/cam cover and I am stumped as far as what to use and where to get it or even what to call it! Need to get some soon im in need of a ride!
    • By ThatE30GUY
      Hey guys, I bought this YZ85 and came to realise the clutch wasnt working, so I drained the oil (Jet black) and pulled the plates out and cleaned them. I assumed finding a torque wrench would be easier than it has been. Does anyone know how to torque the clutch springs to spec without a wrench? Any insight helps.