WARMING UP THE ENGINE.

King Country Chronicle, Volume XXV, Issue 3302, 12 May 1931, Page 2

WARMING UP THE ENGINE.

Cars are equipped with a strangler or choke for use in obtaining a rich mixture when starting the engine. It is a device which is necessary and wonderfully efficient when used properly. Considerable damage may sometimes be caused, however, by improper use of this simple fitment. The choke has a shutter fitted to the air valve of the carburettor, so that the driver can reduce the amount of air drawn in and increase the suction on the jet. This results in a rich mixture being supplied to the cylinders, which in the ordinary way would be far too rich for the work. If allowed to continue it would soot up the insulators on the plugs and reduce the efficiency of the spark and even cause mis-firing. The only reason for the strangler is to put a proper mixture into the cylinders. When the engine has been left idle there is more or less pure air in the cylinders. If the normal mixture were admitted it would mix with this air, and the result would be a weak mixture difficult to ignite. The rich mixture caused by the closed

choke mixes with the air in the cylinders and creates the right mixture for starting. Once the engine is started the choke must be opened. Some motorists try to warm up their engines more quickly by keeping the choke fully closed for an appreciable time. This is a mistake and will often result in serious wear and trouble. If the engine requires warming up before it will pull properly use it in the normal way, with the choke as far down as possible, and run steadily for a few minutes on a low gear.