What is Euro4?

Euro 4 legislation defines the acceptable limits for the emission of pollutants by new motorcycles. Euro 4 dictates how clean exhaust gasses have to be and how much evaporating fuel they are allowed to emit. The standard automotive solution is to vent fuel tanks into a canister. (EVAP canister). Inside the canister is a carbon compound (often charcoal) that absorbs fuel vapour. When the engine is running the fumes are vented back into the fuel system.

Bikes sold in the US state of California have complied with these emission regulations for several years and as a result of this Scottoiler has already been issued with a California Air Resource Board Exemption Order (CARB EO) – an independently tested acknowledgment that fitting a vSystem does not compromise emissions from bikes. In many respects Euro 4 and the charcoal canister make fitting and connecting a vSystem more straightforward.

Identifying the EVAP System

On motorcycles with evaporative systems there will be an EVAP canister installed with hoses running from the petrol tank to the canister, and also a vacuum hose from the engine to this canister.

Connecting the vSystem to the EVAP System

To install the Scottoiler vacuum connection locate the vacuum hose from the engine to the canister. Cut into the vacuum hose and insert the T-piece before the purge valve. Fit the Scottoiler vacuum tubing into the small side of the damper elbow and press the larger side of the damper elbow onto T-piece. Ensure all connections are firmly made.

The T-piece must be inserted into the vacuum hose between the engine and the purge valve.

This is an example of the EVAP system on a Triumph Bonneville which shows the EVAP System and the vacuum pipe from the throttle bodies to the purge valve.

Should you be unsure if your motorcycle is equipped with an EVAP system please refer to your motorcycle manual and our model-specific installation guides.