NOS Harley-Davidson 883 Evolution Sportster Intake Valve 18031-86 | 1986-2003NOS Harley Davidson 883 Evolution Sportster Intake Valve 18031 86 1986 2003 Item Description: This is a genuine Harley Davidson New Old Stock (NOS) Intake Valve for the 883cc Evolution Sportster. This is an original factory part, ensuring the correct metallurgy and heat treatment for your engine rebuild. Unlike aftermarket "one size fits many" valves, this is the exact Part #18031 86 called for in the official Harley Davidson service manuals for the