Cylinder Base O-Ring on Crankcase Stud 15mm OD x 10mm ID - purchase 4 to refresh both cylinders.
Use two O-Rings on the top two cylinder studs of each cylinder - in the recess cut to accommodate them.
Vehicle Manufacturer: BMW
Application: BMW Airhead Models
Make/Model: BMW R45, R60, R65, R75, R80, R90, R100
Model Years: 08/1975 - 1996
Manufacturer #: 11 11 1 262 141