Yamaha YZ125 Phathead cylinder head kit 2001-2004 Chamber selection:Y11 - 10.0cc Stock 1cc (95+ octane)Y23 - 19

1cc (95+ octane)Y23 - 19

CR125 CR250

Kawasaki KX250 2003-2004 Phathead Racing cylinder head kit

KX40  - 7

Kawasaki KX250 Phathead cylinder head kit 2005-2007

Yamaha YZ125 Phathead cylinder head kit 2001-2004 Chamber selection:Y11 - 10.0cc Stock 1cc (95+ octane)Y23 - 19Note: The coolant outlet positioned in the 2005+ model location for better flow. Yamaha YZ125 Phathead cylinder head kit 2001 2004 Chamber selection: Y11 10. 0cc Stock Y12 9. 3cc (95+ octane) Y13 8. 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