Engine sprocket. 4 lobe. Select your number of teeth: 16, 17, 18, 19, 20, 21, 22 or 23.
BSA M20, M21, B31, B33
Chain: 1/2 x 5/16 | 428 | 110046
Part numbers: 16T: 15-1568 | 17T: 15-1567 | 18T: 15-1566 | 19T: 15-1565 | 20T: 15-1564 | 21T: 15-1560 | 22T: 15-1561 | 23T: 15-1562
