Crankcase ventilation check valve, late version ball type check valve lets the air out of the crankcase while not letting it back in. Used on many big twin models 1975 through 2002.
Note: these check valves have been coming in with an internal oring added to assist sealing. Be sure that the oring is seated properly at the base of the valve before installation.
850T3, T4, T5, Convert, G5, SP1000, SP II, SP III, Strada, LeMans III, LeMans 1000 all years LeMans IV and LeMans V, Mille, 1000S, California II, California III, California 1100, EV, EV Touring, Jackal, Bassa, Caifornia Special, Special Sport, Aluminum, Metal, Stone, Daytona 1000, Quota 1000
Replacing earlier part numbers 17150550 and 17150551