Yz 65 piston question

RCF
Profile picture for user RCF
Posts
548
Joined
4/1/2008
Location
PA US
RCF

Just curious, I'm rebuilding a 65 for a guy. Cylinder is stamp C. He bought a vertex b piston which I assumed was the wrong one until I looked up Pistons and noticed pro x the a piston starts at 43.44 b is 43 .45 The vertex b. Piston is 43.46 So does that actually make the vertex a c piston? I can't find the actual sizes of the OEM Pistons anywhere and the top of the Piston isn't stamped like they normally are.

|
RGaede
Profile picture for user RGaede
Posts
209
Joined
1/10/2014
Location
Albuquerque, NM US
RGaede 6/18/2024 8:35pm
6/18/2024 8:35pm Edited Date/Time 6/18/2024 8:35pm

I normally use the oem kit for yamaha top ends, comes with everything you need for a reasonable price.   They show the yz 65 "c" kit as 121.  Rm also shows these piston sizes,  I would double check them vs a service manual. 

https://www.rockymountainatvmc.com/parts/yamaha-complete-top-end-rebuild-kit-p

RCF
Profile picture for user RCF
Posts
548
Joined
4/1/2008
Location
PA US
RCF 6/19/2024 12:36pm
6/19/2024 12:36pm
RGaede wrote:
I normally use the oem kit for yamaha top ends, comes with everything you need for a reasonable price.   They show the yz 65 "c" kit...

I normally use the oem kit for yamaha top ends, comes with everything you need for a reasonable price.   They show the yz 65 "c" kit as 121.  Rm also shows these piston sizes,  I would double check them vs a service manual. 

https://www.rockymountainatvmc.com/parts/yamaha-complete-top-end-rebuild-kit-p

Thanks for that chart. The vertex B is definitely the right one for the c-cylinder. 

Post a reply to: Yz 65 piston question