North American Emissions Plumbing - Twin SUs with Anti-Runon Valve

Hover over a number for the key, click on the menu items below to show the vapour/vacuum routings.

Fuel Flow     Tank Expansion/Contraction     Carb Expansion     Crankcase Breathing     Anti-runon    

Image based on one from the British Leyland Workshop Manual

Fuel is drawn from the bottom of the tank (13) by the pump (20) and pushed through the fuel filter (12) and into the carb float chambers.

In 1978 a second charcoal canister was added below the anti-runon valve (19), to the air vent pipe (20). As the valve was connected to the inlet manifold fumes there could escape to atmosphere via the valve. The second canister trapped these, and was purged in series with the main canister during normal running.