GENERAL DESCRIPTION Some export models are fitted with emission control devices to meet the Emission Control Regulations of the countries in which they are marketed. In Europe, the Control Regulations are met at present by recalibration of the carburettor jets, the idle mixture strengths and the ignition systems. For the North American market, however, with its more stringent U.S.A. and Canadian Federal requirements, an additional air injection system is used to extend the combustion process into the engine's exhaust system by the injection of air into the exhaust ports. This sustains and supports the combustion process beyond the combustion chambers in order to reduce the hydrocarbon (HC) and carbon monoxide (CO) content of the exhaust gases.
The efficient operation of the emission control system depends on the engine being correctly tuned, and for this reason the tuning specifications for engines with emission control systems must be strictly adhered to at all times. These are given in 'Technical Data' at the end of this section.
Proper test equipment is necessary to carry out a satisfactory check of the emission control systems. This is particularly applicable in countries where the systems must be checked in accordance with the local regulations and a certificate issued after the check. In this case, all adjustments and settings on the systems should be entrusted to an Authorised Dealer or Specialist.