Lower Compression Cylinder Head Insert 23-24 300 SX/XC/TC/TX/EX

This lower compression, than stock, head insert, is the remedy for more mid to top power on the 23-24 300 SX/XC/TC/TX/EX bikes.
 
This would lower your compression around 15-20 psi from where it is now..  The reading of 185 psi ( shown ), is taken at 100 ft above sea level with a .045-.050" base gasket thickness.  This made the squish band clearance 2.3 mm or .090".
 
This dyno run increase you see, was with these specs over the stock SX insert.  It's compression was 205.
 
Made from 2024 aluminum, so it won't crack under pressure.  Perfect for offroad, desert and motocross.