Kawasaki KX100 Phathead Combustion Chambers GASGAS Yamaha YZ250 Phathead cylinder head

Yamaha YZ250 Phathead cylinder head kit 1999-2026

YZ80 YZ85 (2003-2021)

TTR250 YFM250 Bear Tracker YFM350FW Big Bear 4x4 YFM350U Big Bear 2x4 YFM350X Warrior YFM600FW Grizzly 4x4 YFS200 Blaster YFZ350 Banshee 1998

We have a batch in process

KX85 & KX100 up to 2013 (see other cap for 2014+)

Kawasaki KX100 Phathead Combustion Chambers GASGAS Yamaha YZ250 Phathead cylinder headChamber selection: KX40 7. 4cc Stock compression KX41 6. 4cc (95+ octane) KX42 6. 0cc (100+ octane) KX43 5. 6cc (105+ octane) KX Stroker insert for Hotrods crank (listed as +4mm) is actually a +2mm Hotrods has only one part number for the stroker so we are sure that there is not a +2mm and +4mm If you have a Hot Rods stroker crank our insert will work