Yamaha YZ65 2018-2025+ Phathead cylinder head kit CR85 big bore kit In addition to the head

In addition to the head you will also receive a customized dog tag with the same etch that goes on the head adjusted to best fit the tag

mapping suggested

4cc (110+ octane)

Remove the original guts from the stock plastic cap and install into the new billet shell

Yamaha YZ65 2018-2025+ Phathead cylinder head kit CR85 big bore kit In addition to the headYamaha YZ65 2018 2025+ Phathead cylinder head kit Chamber selection: YZ65 5. 2cc stock YZ66 5. 0cc 95+ octane YZ67 4. 8cc 100+ octane Phathead Kits include a head shell with one combustion chamber, two sets of o rings, 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