Honda CR125 Phathead combustion chamber

Honda CR125 Phathead cylinder head kit 1992-1999

Chamber selection:

H13  - 6.7cc stock compression

H14  - 5.8cc high compression

Honda CR125 Phathead cylinder head kit 2000-2003

Chamber selection:

H11 - 8.2cc Stock compression

H12 - 7.6cc (95+ octane)

H13  - 6.7cc (100+ octane)

H14  - 5.8cc (105+ octane)

Honda CR125 Phathead cylinder head kit 1988-1991 and 2004-2007

Chamber selection:

K10 Stock 

K11 - 9.2cc  (95+ octane)

K12 -  8.5cc (100+ octane)

K13  - 8.2cc (105+ octane)

K14 - 7.6cc (110+ octane)