The Orange or Red Color Main Metering Gasket made by Tillotson for the exclusive IAME engine’s technical rules. 

The color is to give tech officials and scrutineers a quick visual check without the need to measure the gasket. This is usually required to be legal especially national events but the rules are not as strict on the club and local levels of racing. In those cases, you can use the standard 16B-217 Tillotson Main Metering Gasket. Check with your racing organization or club’s rules and officials before ordering.

16B-406 Tillotson Orange/Red Spec Metering Diaphragm Gasket fits all HL, HR, HW, HM, HX, HB carburetors but is mandated by the HW-27, HW-31, HW-33 for IAME Class Engines