Care Of The Car

Northern Advocate, 9 July 1938, Page 15

Care Of The Car

Apart from such obscure ills as arc caused by a shaky ignition condenser, a faulty coil or derangements to the interior mechanism of the carburettor, the- maintenance of a modern car engine in a reasonable state of efficiency is not very hard, and is well within the abilities of the average owner. Carbon formation and the reseatingof the valves affect performance considerably, and should be attended to by a skilled mechanic at regular periods. However, there are several other things which will cause rough funning and loss of power, but which are easily put right. Such faults may be prevented by a regular system of engine tuning. If the following simple tasks are performed at intervals of about 5000 miles, then, with reasonable luck, the engine will always operate satisfactorily, and it will only be the unexpected and rare breakdown of important units which

will be likely lo give cause for anxiety. First, the owner should remove all the plugs (being careful that the hightension leads arc not mixed), clean them as well as possible, and adjust the gaps to- the clearance recommended by the manufacturers, a feeler gauge of-the proper thickness being used to set the gaps. If the gaps have been burnt excessively, the plugs should be removed again within the next thousand miles and examined once more, because the makers sometimes fit plugs too ‘‘hot” for a particular engine, so that their points become incandescent, causing pre-igni-tion, and rapid burning of the electrodes themselves. Such a mistake on the part of the makers is not as rare as might be imagined. When It has occurred, the plugs should be thrown away, and now ones fitted. They should be chosen on the advice "of the agents or makers, because plugs that arc not suitable affect efficiency. If left in the car. the electrodes will eventually burn right away.

The platinum or tungsten points of the contact breaker in the ignition head will also need some attention. They should be removed, cleaned carefully with a fin.e magneto file (if they are only blackened and not pitted, the carborundum paper on the side of a match box will serve), and carefully replaced. They must new bo set to the required gap when opened by the small cam, the gap generally being about .018 inch. In order to open the points for checking with another feeler gauge, it may be necessary to turn the engine slightly, so that the rocker arm carrying one of the points, rises on the cam.

The next step is to clean cut the water and dirt from the carburettor, but on no account ; meddle with the fixed jets or metering pin.

The only part of the carburettor which the owner can touch is the slow running jet. Start the engine, warm it up thoroughly, and then turn ir and out the small adjusting screw on the carburettor barrel until the position is reached where the engine fires evenly at idling speed on the leanesi possible mixture. Turning the screw in makes the mixture lean, and screwing it out makes it rich. If, after these things have beer done, the engine still inclines to run roughly, it is possible that the tappet; are out of adjustment. Valve tappel adjustment is sometimes a little trickj for the amateur, partly because tin tappets are often inaccessible, anc partly because sometimes three span ners have to be used, one to preven the tappet from turning, another tc hold the locknut, and another to turn the head. It should not take long

however, to master this little job. One further point should be mentioned in regard to them. Often there is a certain amount of looseness in the thread of the tappet head, so that when the locknut is tightened down it raises the head and destroys the clearance which has been set so carefully with the proper feeler gauge. Therefore, leave the locking nut just tight enough to take up such looseness while the adjustment is being made.