MOTORING NOTES.

Digger (Invercargill RSA), Issue 39, 10 December 1920, Page 13

MOTORING NOTES.

EXPOSED BRAIiE PARTS. Much trouble with brakes is due to mud and wet and rust in tlie toggle le\ers, outside levers, or in the bearings of the lever rods from outside into the interior of the drum. These are in a very exposed position, and are often neglected as to lubrication. They should have big screw-down greasers, which should be regulariy attended to. A good deal of skidding and danger is due- to brake levers and toggles working stiff on one side while the other is free. The brake compensating gear cannot deal with this irregularity, and slndding results when the brakes are applied. THE MOTOR CYCLE CHAIN. Motor cyclists should remember that a loose ehain not only wears itself out, but wear.3 the tops of the sprocket teeth. They should be kept adjusted at proper tenrion at all times. Chains have a tendeu lo wear unevenly throughout their leogth. Rotate the sprocket and make the adjustment with the chain at its tight. est point. Proper tension is had when tlie chain hangs in a straight line between the sprockets without b.eing rigidly ' tight. Careful attention to chain adjustment will save pounds in the course of a machine' s life, and reward the rider with vastly smoother rumling. CARBURETT0R TROUBLES. When an engine, after starting, runs for a minute or two ^nd stops, the first place to look for the trouble^ the petrol i'eed line. A partial. stoppage in the fuel supply pipe will lessen the fiow of i'uel so that the float chamber fills slowly. On being started, the engine will quickly consume the benzine in the chamber and stop. Another possibl'e cause for the fault is the float sticking, and if the float sticks in the high position the fiow of fuel will be greatly lessened or may be stopped entirely. Water in the petrol is also troublesome as a di'op may get into the feed pipe or the spray nozzle and interfere with prompt starting or reliable feed of fuel. Lint or other foreign matter around the filter screen in the feed line is also responsible for restricting the fuel, especially in cars using the gravity feed syst-em. A CHATTERING BRAKE. One of the common troubles eneountered In the brake assembly is a tendency to chattering, which is extremely annoying. This is generally induced by a deposit of the burnt oil on the bands and it may generally be cured by applying hot kerosene oil to the part®. If this does not serve, the only remedy is to burn off the deposits with a blow torch. This operation is carried out by removing the bands and soaking them in petrol over n'ght and then applying the torch.. The propellor shaft brake is peculiarly liable -to this trouble as if the transmission case contains a little too much oil, the excess lubricant is thrown thr.ough the shaft brushing on to the bands. If an application of graphite i.s used instead of oil for lubricating the brake bands, it will lessen this trouble. LUBRICATION OF SPRINGS. Springs wear at tlie shackles, and at the trunions in the case. of thqse springs of the cantilever variety. '• This wear is generally due to lack of lubrication. Shackle bolts have worn nearly in two through neglect in this rospect. These small items require conscientious attention, and naed a regular renewal of grease at stated iatervals. The lubricators are often placed in awkward and incessible positions, but this should be no reason for neglecting them. It is a good plan to make a list of those occasional lubrica.tions which should be carried out, and to note the speedometer mileage on each occasion when these receive attention. Using the mileage recorder in conjunction with such a list will add to the life of the car and often render renewals unnecessary or infrequent. NOISY GEARBOXES. Noisy gearboxes are a great eource of annoyance to the careful motorist. If the bearings of a gear shaft get worn, the pitch eircles of the engaging teeth fail to coincide, and the teeth of the gears meet- each other at the wrong part of tlieir Cbntour. This causes excessive wear, since the teeth slide instead of rolling upon each other, as they are theoretically designed to do. A worn epigot bearing between the primary shaft and the second shaft will cause the azles of the gear shafts to get too far away from each other

at one end and cause the teeth to meet at the edges instead of all along the face. This causes excessive wear and noise. ' Gear shafts should be periodically examined, and when undue wear is apparent the spigot bearing should be re-lined, if it is of the parellel type or new ball-bearings should be fitted, The same applies to tho bearings of the mainshaft. THE SPARKING FLUG. The modern spark plug operates for extremely long periods without giving trouble, but occasionally the motorist encounters persistent plug trouble and cannot explain the cause. Plugs as now made, should not give trouble for six months if the opcrating conditions are right. The greatest source of plug failure may be traced to leakage in the plug itself. This refers to hot gas leakage brought about by non-gas-tightness of joints in the plug. The loss in poVer due to reduction in compression pressure is hardly worth considering as compared with the damage done by the heat of the gases. The " excessive ' heat causes insulators to crack and because of carbon contained in the gas there is a black sv^t deposited which also interferes with plug operation. Where the plngs are so located as to receive- no benefit from jacket water'the conditions are stili worse;. because such plugs run normally hot. GRIT IN WHEEL HUBS. T'hose motorists whose vehicles are fitted with detachable wheels should make a special point of seeing that the hubs and the wheel hub" shells are quite clean and free from dust, mud, or grit before attacliing the wheels. Otherwise the wheels will inevitably become loose after the car has travelled even a short distance. Grit prevents the wheel beine: pusehd home on the taper seating, and when locked tight it is actually locked on to the grit; When the vehicle is driven the load pulverises the gritty particles, and the wheel will be found to be loose. If this looseness is allowed to continue, it results in the bedding surfaces of hub and shell beeoming distorted, and the result is a permanently wobbling wheel. The hub of the wheel should be carefully cleaned and greased, and the greatest care should be taken to ensure that no foreign matter gets between the hub and the shell.