Yamaha YZ85 YZ80 Phathead cylinder head kit 1993-2018 Color:Gold K51 - 42cc Stock compression

K51 -  42cc Stock compression                                                                                            K52 -  40

CR500 models 1999 and older

Kawasaki KX100 Phathead cylinder head kit 1991-2021

CX 65 stock compression

S21 -  20

Yamaha YZ85 YZ80 Phathead cylinder head kit 1993-2018 Color:Gold K51 - 42cc Stock compressionYamaha YZ85 Phathead cylinder head kit 1993 2018 YZ80 Chamber selection: Y01 6. 4cc StockY02 6. 0cc (95+ octane)Y03 5. 6cc (100+ octane)Y04 5. 2cc (105+ octane) 52. 5mm big bore chamber 100+ octane for use with big bore piston 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