1947 16h timing chain

Hi Bob,

Details of the magneto chain attached. This is from the Reynold catalogue.

Hi Bob,

   These engines changed in late 1947 from the earlier Franks engine (clock-wise tight wire advance) to the Hopwood engine (anti-clock slack wire advance). The important change was from the early 15 tooth sprockets to the later 16 tooth ones.

Do you have lever followers or the more bulbous later timing cover with circular tappets ? The crucial aspect is "model year" rather than production date. Norton began to produce 1948 models in September 1947. As per Richard Cornish's advice...count the teeth on the sprockets.