MOTOR-CYCLING.

New Zealand Herald, Volume LXII, Issue 19031, 30 May 1925, Page 12 (Supplement)

MOTOR-CYCLING.

The 1904 J.A.P. engine was one of the first overhead valve engines produced in , England. . / J, The opening meeting of the. Brooklands 1925 racing season was well patronised, the majority of the wins going to Douglas and Zenith machines. A number of state police-constables in Saxony have recently been equipped with side-car outfits to assist them in dealing with an ever-increasing volume of motortraffic. 1 Another English car to appear on the local roads is the. 10 h.p. Singer. I' it ted with an o.h.v. engine, disc wheels, and an orthodox three-speed gearbox, it is a ve»y big proposition to the car which bore the same name in 'fire-war days. The following telegram gives further evidence of the successes of British motorcycles. " B.S.'X. overhead valve combination wins 350 c.c. (2j{li.p.) class of Grand Prix rle Lyon averaging 76 kilometres per hour and making best, time of side-cars irrespective of class." Every magneto, should be oiled every ]OOO miles with magneto oil or 3-in-one. 'Hie contact breaker points should be examined ovico a mouth and cleaned and dressed if necessary. L'se saridpader 00 grade for dressing the points. Do not use emery cloth; it leaves small particles on the points which cause trouble. The annual meeting of the Sports MotorCycle Club was held this week, when the following officers were elected for the coming year:—President, Mr. E. O. Jones; vice-president, Mr. \\. Wadluun; < secretary, Mr. N. • Hun!; committee, Messrs." W. Laird, ,T. Kilgour, Coleman, C- Lord, C. Hamblin, C. \ oung. Something novel in the way of motorcycle outings will be held bv the Sports Motor-Cycle Club on June 21. '-I his is to take the form of a number of tests, none of which will be known to competitors until they assemblo at the starting post. A first prize of £5 and a trophy for second place. The entrance fee is ! 3s. The run will be called the "Sports' 1 Scramble." Ten minutes on the road with a modern motor-cycle leaves a lasting impression of efficiency. Always a little more power than you anticipate, always that little extra "turn of speed that satisfies, and, above, all, the deeper satisfaction of knowing that tlio new mount with ail its extras costs less than its predecessor of pre-war days. While the winter overhaul is under way is tiie time to consider converting the old-fashioned "semi-automatic" oiling system to the new automatic pump feed. Tin- conversion is a simple matter and the satisfaction it , will give is enormous. ' Mechanical lubrication is as great an advance on the "drip feed" as this latter was over the plunger pump type. I Assuming the compression of the engine is good and the ignition sufficiently / ad.vv.nced, if is possible that wastage of pefcrj: may he caused (a) by flooding of the carburettor, (b) by the use of too • big a, jet, and (c) by leakage at one or more of the unions. There should be ne trace of wetness below the jet chamber when the machine is stationary; if there is, it is (1) because the level of the petrol in the jet js set too high, or (2) // because the needle valve is defective. With many typfes of modern carburetter it is impossible to discover the exact level of the petrol in the jet, which should be jujt not running over, and more frequently the cause of flooding lies in a particle of grit having lodged on the seating. Keep the chain at the proper tension / at all times. This can lie determined by lifting the bottom of tlio chair at its centre..' ; It should only lift, about one inch" if properly adjusted. A loose chain may jump the sprockets and damage spokes and chain guard. Tight chains cause extra wear on the bearings and result in chain breakages. About every 500 miles, disconnect and remove the chain. ' Clean it with kerosene thoroughly, theft wipe it dry and dip in a mixture of light cylinder oil and graphite. After an hour hi the mixture, hang the chain up to drip. When all dripping ceases wipe off excess mixture, and oil, anil put tho chain on its sprockets. Be sure that the dip of the detachable link snaps into proper position. 'Keep tyres hard. The, nsc of a pressure gauge is recommended. It is not expensive and will more than repay its cost in increased tyre mileage. Hiding a tyre, soft causes lim-cutting and break- / age of tho fabric as well as rendering the tyre moro susceptible to puncturing. Biding a tyro flat for any distance will ruin both tube and casing. Look after everv cut in tho casing. A cu*. allows watc,: and sand to enter and rot the tyre. Clean the cut and vulcanize it immediately. ' Inspect each tyre every few days for cuts, etc. Be sure to carry a. generous supply of tyre patches anfd cement and have them packed against damage from tools in the tool box. Keep the nut on the valvo stem tight against the rim to prevent creeping of the tube. Keep the cap /of the tyro valvo screwed /on tightly. If the pump becomes dry or leaks, "inject a few drops of light oil in the barrel. // A smallish engine will sometimes start up moro easily if tho valve lifter bo not operated before kick-starting. Most touring engines of the 250 or 350 c.c. type can be "kicked over compression" without difficulty and will then start away at the first attempt., Even engines of larger size can bo started in a similar manner, and it is worth bearing in mind that, in the event of the valve-lifter cable breaking, / practically any engine can lie kicked over compression if, before attempting to actuate the kick-starter, top gear is engaged and the machine moved backward until the piston comes up against the reverse of the,/ compression stroke, and then, the gear lever being moved once more to neutral, a vigorous dig given to the kick-starter pedal. The momentum /gained will be sufficient to bounce practically any engine over. compression. STJPEKCHARGING. f The following is copy of a letter sent to tho Motor Cycle by Douglas Motors, Limited, and contains .interesting in forma- i tion;— Sir, —We beg to draw your attention to the paragraph in your recent article relating to supercharging by means ot an air box, developed by Douglas motor-cycles at Brooklands track. We would poiiit out that this system has not been discarded, and lias been conclusively prove to be of great value, from the point, of view of increased speed / and belter 'gas'distribution. The, same, device is in use "on our latest racing machines. »' We would also say that we have conducted a series of tests, and have aeinal figures in our possession, showing tho amount of supercharging possible, with this device at varying air speeds. Also, i atmospheric conditions are much less ef- j fective than when employing the orthodox carburetter arrangement. I For the T.T. races, the machines were, j found to be quite fast enough with the air ] intake facing to the rear, which was j adopted to eliminate the possibility of j small stones and dust, etc., entering the cylinders, had the, air intake been lacing ~ forward, but the whole value of the ap- / .paratus is seriously decreased when this method is adopted. Finally, we would mention that, our iystein has been' taken up by that very high-grade production, the Mercedes car, / that is plating the, carburetter between tho Jiupercharger and the engine, tho float chamber and patrol ■ tank being balanced jn relation to the supercharger, the difference being, in the case of the Mercedes, Bootes blower is used in place of the |>roj*cciting a:;." scoop.