Your Norton— Its Care and Maintenance

Sun (Auckland), Volume I, Issue 184, 25 October 1927, Page 7

Your Norton — Its Care and Maintenance

A SUN special feature to assist the owner-driver to obtain the maximum results in performance bjj the proper care and treatment of his car.

An engine may give good service for many thousands of miles if satisfactorily lubricated, or may be ruined in a day if this is neglected. It is impossible to lay down any hard and fast rules for lubricating, the amount of oil depending entirely upon conditions, but be sure to give enough, it being safer to err on the generous side and over lubricate (which necessitates more frequent cleaning of the engine or causes an oiled up sparking plug) than to be too sparing of oil, which means frequent re-brushing, new piston rings, etc., unsatisfactory running, and finally, a ruined engine. The special sump at the bottom of the Norton engine permits a good quantity of oil to be carried without rapid changes of level. Then, for ordinary quiet running, set the regulator to pass about 30 to 40 spots a minute, or so that the pump empties itself once every seven miles. (This may need to be varied with different oils, individual engines, and drivers, but generally speaking, it is about right.) Increase the quantity if the roads are heavy. Always give a little more when climbing a hill, or when driving against a strong wind, and when driving at continued high speed with full throttle, the engine should be given at least three times the amount of oil used for low speeds. Drain out the crankcase at intervals of not more than 500 miles; better to do it oftener if convenient. Replenish with five or six oil charges in the case of a Big Four machine, and eight to ten charges both for the O.H.V. and 16 H. models. In the case of the O.H.V. engine, the timing gear case acts as an additional sump, and after dismantling it is necessary to see that this sump is supplied with oil. .. Should it be necessary to dismantle the timing gear, be sure that the valve rockers are put back right. Should you get the rockers mixed examine the shafts they pivot on. One end of each shaft will be ground plain. The other end has a “centre” mark. Remember always that the plain end of each shaft goes in the panel cover and you cannot then assemble them wrongly. The cam wheels are not marked m any way, but if you are doubtful as to your ability to replace them correctly, a scratch or pencil mark can be made on them, say on one tooth of small half-time wheel and two marks on cam wheels. As both cams mesh with the half-time pinion, it will be necessary to mark the latter in two places, e.g., where each cam wheel meshes with it. Surplus oil should, of course, be marked from the wheels before marking them. The timing pinion is keyed on to a taper shaft. Remove the lock nut which holds this in position,. and detach the pinion in the manner indicated in the case of the engine shaft sprocket. Remember that the lock nut is left-hand thread. There may be one or more packing washers behind the pinion. If so, do not lose them. When removing this pinion the piston and cylinder must be in position, as otherwise the connecting rod will get damaged. To adjust for correct clearance between tappets and valves, special spanners are provided in the tool kit. With one spanner on the hexagon of the tappet and the other on the hexagon on the tappet head, unscrew lock nut (right-hand thread) until correct clearance (approximately .006) has been obtained. Then remove the spanner from the tappet stem and tighten the lock nut against face of the tappet head. Be careful to see this is locked up tightly, otherwise there may be disastrous results. The correct timing is as follows:

BIG FOUR Exhaust valve commences to open .7-Bin before bottom centre. Exhaust valve closes 7.32nd inch over top centre. Inlet valve commences to open 7-32nd inch before top centre. Inlet valve closes 11-16th inch up compression stroke. THREE AND A-HALF H.P. Exhaust valve commences to open 7-Bin before bottom centre. Exhaust valve closes 3-16th overtop centre. Inlet valve commences to open 3-16 before top centre. Inlet valve closes 5-Bin up compression stroke. A difference from above figures of l-32in in opening of inlet or closing of exhaust is of no consequence. The gap between the valve and tappets should be approximately sixthousandths (this will admit a thin 'visiting card). With contact breaker fully advanced the platinum points should be commencing to open: Big Four, Jin; and 3 h h.p. 3-16 in before top centre on compressor stroke. The gearbox should be washed out with paraffin and fresh oil put in, say

every 500-800 miles. To do this remove plug situated on kick-starter side of gearbox and squirt in paraffin. Replace plug and kick round by means of the starter several tiriies to enable the paraffin to get everywhere. Then remove drain plug underneath gearbox and drain off. Pour in fresh engine oil, say a teacupful, having replaced drain plug, and kick round a few times. Then drain off again. This washes out remains of paraffin. Then pour in fresh oil until it can be seen approaching base of filling hole. Should gears ever get out of adjustment, proceed as follows: —Place gear lever in the “neutral” notch (this is the small notch on gear quadrant between “bottom” and “second” gear positions), detach yoke end joining gear lever to rod, which descends to gearbox. To do this remove split pin and washer and pull out small bolt which goes through yoke end and eye of gear change arm. Now unscrew or screw up, operating rod as the case may be, and reassemble. When adjusted correctly, the back wheel can be turned round without revolving the engine. Make a point of testing the security of all nuts occasionally with a spanner. Try the steering head, the back and front wheels, and sidecar wheel for shake and if slack, DO NOT \VAIT UNTIL TO-MORROW —but ADJUST IT NOW.