cr 125 rebuild

[Cr125zrule]

hey guys..im finaly going to rebuild my top end as it lost compression on saturday...took the head of and barrel everythin is in good shape but the ring has a slight dip in it in and some black oil marks are on the piston diretcly under were the dip is in the ring ....its a single ring piston...were would i get a new ring for it and how mucth would it be in £...please help me its a 97 cr 125lewis

[Faded]

Not sure what you mean by 'dip in the ring', maybe you could snap a pic or elaborate for us? The black/oil mark below the dip sounds like blowby, which is a sign of ring wear/worn top end. You make it sound as if you have a lot of hours on this bike, if that's the case it might be in your best interest to replace the piston along with the rings.

[Cr125zrule]

hey dont worry the ring was worn and ive chnaged it shes got compression and is running perfect ....thanks

[ossagp]

I think he was referring to the notch that in worn in where the bridge is. An extra oil hole will help that the next time you rebuild. Sometimes it is made worse by carbon buildup, or too light in the oil mix. If it got 10 hours on it with healthy compression, I would probably not change anything based on that alone though.

[Cr125zrule]

thanks