O-ring for sealing the outer body of the throw-out bearing assembly
Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police models
There are two sizes of outer bodies. 20 mm diameter outer bodies were used on the early 4 speed transmissions. 22 mm diameter outer bodies were used on the later 4 speed transmissions and all of the 5 speed transmissions. These measurements were made to the best of my ability.
20 mm diameter outer bodies
MG# 90706150: 15.3 mm ID × 20.1 mm OD × 2.4 mm wide
A -113
x-ring of the following actual dimensions also works well (contributed by Tony Sciandra of Caffe Fresco Specialty Coffee Roaster on the old Yahoo! Loopframe_Guzzi news group (which has now moved to Groups.io)): 0.549 inch ± 0.007 inch ID × 0.755 inch OD × 0.103 inch cross-section. Nominal dimensions are 9⁄16 inch ID × 3⁄4 inch OD × 3⁄32 inch cross-section. This x-ring can be purchased from Precision Associates, part number 4444-113 or McMaster-Carr part number 90025K228.
22 mm diameter outer bodies
MG# 90706170: 17 mm ID × 22 mm OD × 2.5 mm wide