This is a replacement thermo carb insulator gasket for O.S. 20K/21C/20L/21H/21J carburetors. This is the small gasket that goes between the carburetor and the engine crankcase to stop heat transfer from the crankcase to the carburetor. This fits on the O.S. 21 VZ-B V-Spec and 30 VG engines.
Wednesday, Jun 2 2010 (about 10 years ago)
O.S. Thermo Carburetor Insulator 20K/21C/20L/21H/21J
If you get this stuck in a motor, heat up the engine to running temp and work the carb in and out to remove it.