144cc ATHENA racing kit for Yamaha YZ 125 motorcycle from 1997 to 2004

Here is the best way to reliably upgrade your Yamaha YZ 125 - 1997 to 2004 from 37.5hp to 42hp!

The ATHENA BIG BORE with its large diameter of 58mm offers a good performance and torque gain over the entire range to your YZ 2T.

The kit consists of a very reliable ATHENA nicasil treated aluminum cylinder with corrected diagrams. A VERTEX grphité piston forged mono-segment steel.

WARNING: To assemble this kit on YZ 125 LC 1997-1998 models you need to replace the stock muffler with a year 1999-2003 version and for 1997-1999 models you need to order the stock springs 2 twists)

It comes with screws and gaskets, cylinder head, piston, unloading valves ... as well as the instructions as in the photo!

Mounts on Off-road (mx) Yamaha YZ 125 - 1997/2004