Triumph Rat Motorcycle Forums banner
  • Hey everyone! Enter your ride HERE to be a part of October's Bike of the Month Challenge!
1 - 2 of 2 Posts

·
Registered
Joined
·
1 Posts
Discussion Starter · #1 ·
What is the correct ratio for the chronometric tachometers with the built-in tachometer gearbox in the timing cover? It is driven from the exhaust cam so runs half engine speed. Does it need a 2:1 or a 1:4?
 

·
Registered
Joined
·
1,458 Posts
Hi and welcome! You need the 4:1 ratio BUT, you also need it to be ANTI CLOCKWISE rotation. The number you need to look for on the clock face is, DYNAMO engine RC109. ALTERNATOR engine RC126.
Roy.
 
1 - 2 of 2 Posts
Top