LIGHT-WEIGHT MACHINES.

Auckland Star, Volume LX, Issue 172, 23 July 1929, Page 17

LIGHT-WEIGHT MACHINES.

MERITS OF THE TWO-STROKE. \t the present time, when efficient hi»h compression overhead valve engine? are so popular with speedmcn and sportin" riders, the- everyday motor cyclist is "inclined to be governed by track and beach successes, thinking that if this tvpe of engine is satisfactory for competitions it must be the ideal for averse road work. Many mfahines working under a compression ratio of seven to one and upwards, fitted with close ratio gearboxes, are designed solely for speed and if ridden on country colonial roads in wet weather would be practically useless. To the person who acquired a machine essentially as a utility mount and is desirous of a trouble-free, economical method of transport, the twostroke engine appeals very strongly. Where the two-stroke engine has the oreatest advantage is general upkeep and maintenance. Having only three movin" parts, namely, piston, connecting rod and crankshaft assembly, there are not any valve rockers to lubricate, no tappets' to wear away their fine adjustment on which so much depends, no valves to grind, no springs to lose thentension or break, and, lastly, a feature which few motor cyclists fully realise, no mechanical clatter. When a two-stroke engine is new it is invariably rather stiff, more so than its larger 'four-stroke brother, _ and if after three or four hundred miles the engine is still stiff the owner should noL be°alarmed, for when it is finally "run in" one could not wish for a more willing worker. It is reluctantly admitted that the two-stroke engine will not idle perfectly at small throttle openings, but as soon as the motor is called upon to exert some of its power it immediately runs evenly and sweetly. This is not detrimental to the engine in any way. the only objection being the irregulanty of the exhaust. Riders of large touring machines should not regard small twostrokes as ''feeding bottle buses," for behind that gentle purring exhaust note lies abundance of power and often a speed up to 60 miles per hour.