Honda CR250 2005-2007 Phathead cylinder head kit cobra CX51 (100+ octane)

CX51 (100+ octane)

AY21 - 21cc  (95+ octane)

We also suggest the dual ring piston for the 2014+ KX100

Yamaha YZ85 Phathead cylinder head kit 2019-2026

Honda CR250 2005-2007 Phathead cylinder head kit cobra CX51 (100+ octane)Honda CR250 Phathead cylinder head kit 2005 2007 Chamber selection: H30 21. 8cc Stock H31 20. 6cc 95+ octane H32 19. 7cc 100+ octane H33 18. 5cc 105+ octane H34 17. 4cc 110+ 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