[Vicky]

Touring Engines depend on the builder, but the changes usually involve: Inserted Rod & Main Bearings, Counterweighted and Balanced Crankshaft, Bronze or Aluminum Timing Gear, Higher Lift Camshaft (lobes may have greater seperation for broader power band) and a Higher Compression Head.

Carburation, Ignition and Exhaust System changes may also be involved to increase reliability or performance (there is a balance between performance and reliability).

Hope this helps clarify the changes.