Triumph Rocket III Classic Service Manual page 413

Fuel System/Engine Management
Evaporative Loss Control System - California Models Only
California Models Only
All California models are fitted with an evaporative emissions control system to prevent the exhausting of fuel vapour into
the atmosphere.
A canister containing activated charcoal, located beneath the left hand side cover, absorbs hydrocarbon vapour given off
by the fuel in the fuel tank. Vapour delivery to the canister occurs at all times, but is particularly high after riding, when the
motorcycle is parked in direct sunlight or in high temperatures. This causes the fuel temperature in the fuel tank to rise,
resulting in a rise in the vapour pressure inside the tank. Normally this vapour would be vented to atmosphere but on
California models, it is stored in the charcoal canister.
When the engine is started, the vapour is returned to the throttle body by means of induction vacuum, and is burnt in the
engine.
There are two distinct phases to the system's operation, engine off and engine running. These two conditions are
explained overleaf.
Component Locations Call situated behind the left hand side cover)
1. Carbon canister
2. Purge vatve
3. Canister ties
4. Purge valve control
Service Manual - Rocket Ill/ Classic / Touring
11.209