Yamaha YZ250 combustion chambers KTM 5mm big bore chamber 100+

5mm big bore chamber 100+ octane - for use with big bore piston

Flex on the competition with our signature geometric designs carved out of solid 6061-T6 billet aluminum

Honda CR125 Phathead cylinder head kit 2005-2007

SX52-09 (105+ octane)

We will have a more comprehensive list soon

Yamaha YZ250 combustion chambers KTM 5mm big bore chamber 100+Chamber selection: 1999 2022 Y20 22cc Stock compression for the X model Y21 21. 1cc Stock (91+ octane) Y22 20. 1cc (100+ octane) Y23 19. 1cc (105+ octane) 1999 2022 big bore chambers: YZ295 24. 8cc 72mm 93 octane Revised squish clearance . 055" YZ296 24cc 72mm 100 octane Revised squish clearance . 055" 1988 1998 Y30 stock Y31 (95+ octane) Y32 (100+ octane) Y33 (105+ octane)