Need somone of knowledge! Con rod/pin bearing/ Yz 125


Oct 8, 2004
Ok, I will tell you the whole story. I bought a bike off a local shop, wich I thought to be knowledeable! The guy does some decent work but he isnt very reliable. So, he told me it had a 136 BB. I bought it, with realy no problems. After about 10hrs on the bike I found out I was mixing 50:1! Also running up a hill wide open then letting of the gas doesn't help. Doing that screwed up my bore and piston. So, I had the guy put a sleeve in it and I bought a new wisco piston. Everything is standard now. Well, last night I went to put it together and I found out that it has a Hot Rod. Well, I go about putting it together and then I realize that the old wristpin bearing is to big for the new wiseco pin. The old bearing fit the rod perfect and the old pin but the ID is to big for the new wiseco pin. The old pin is also a little bit longer than the new wiseco pin. What is up with this? I am guessing it is because of the 136. What can I do? Do I need to find a bearing that will accomodate the new pin and rod? The number on the rod is C.K 104
Eric or Rich or someone that knows these engines or has a solution please help! It is a 2000 Yz 125 I can get some pictures if that will help.


Nov 5, 2001
just measure the ID of the rod, the OD of the pin and the width of the old bearing and get the bearing from the Wiseco catlogue.

i bet they ran the rod from the newer bike, so i would guess an 01 and newer bearing would work.
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