Yamaha Athena YZ125 144cc 58mm Big Bore Cylinder Phathead version 2022-present KTM 2cc Stock compression

2cc  Stock compression

9cc (100+ octane)

Y32 -  (100+ octane)

SX50-09  Stock

Yamaha Athena YZ125 144cc 58mm Big Bore Cylinder Phathead version 2022-present KTM 2cc Stock compressionWe replicated the Athena chamber to offer the best performance for your two stroke big bore kit. Athena YZ125 58mm 144cc big bore compatible. Phathead Kits include a head shell with one combustion chamber, cylinder head nuts, copper washers, some stickers for your bike and tool box and installation instructions.. Phathead cylinder heads are made of 6061 T6 billet aluminum. The material is stronger and transfers heat better than cast aluminum. The two