Yamaha YZ65 2018-2023+ Phathead cylinder head kit

Yamaha YZ65 2018-2023+ 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 aluminum.  The two piece design allows an increase in coolant flow as well as surface area which improves cooling for better consistency and performance.   

One of the main benefits of the product is the replaceable combustion chamber which are available in a range of compression options.

Suggestions : Swap chambers to adjust performance for a variety of riding conditions and track types or keep a spare in case of engine failure.