FOR some time past the Sparkbrook Company have been experimenting with a two-stroke machine, and it is many weeks ago since we took our first ride on the new model. At that time, however, the policy of the company was not definitely settled, and consequently we withheld any reference to this new model.
The engine used is the 2¼ h.p. 70 x 70 mm. Villiers, with the usual neat arrangement of double silencer and magneto plate. A chain transmits the power to a two-speed gear, which is quite one of the neatest and soundest pieces of work we have yet seen on a small machine. The gear is of the usual dog clutch type, and both wheels and shafts are of the finest obtainable material, while all bearings are of the Skefko double row ball type with felt washers arranged to prevent oil leakage.
Oil leads have been formed wherever necessary, and the single bolt which is used to hold the box in position is of large diameter and hollow, so that it forms a convenient oil filler, and, by the addition of a small gauze filled cap, acts also as an air vent. This has proved to be an excellent feature, as it helps greatly to prevent oil leakage. In fact, we may say that the Sparkbrook two-stroke is one of the cleanest machines we have yet ridden. A 7in. pulley is used for the final transmission, and the front portion of the rear mudguard will be extended below the belt, a feature which almost eliminates belt slip even in the worst weather.
Lubrication via the Inlet Pipe.
Lubrication is simple in the extreme, for a Best and Lloyd semiautomatic lubricator supplies oil direct to the inlet pipe, whence it is sucked into the engine and circulates in the usual manner.
A Senspray carburetter with a neat and very effective intake shield is utilised. The tank has a capacity of one gallon of petrol and one quart of oil, and is neatly finished in black and green. The frame is very neat and strong, the head lug being a particularly sound piece of design. The control for the two- speed is very simple, being so arranged that a single-geared machine can be converted to a two-speed model by quite an amateur.
Aluminium footboards, a stout carrier, 26in. x 2in. tyres, and excellent fittings and finish combine to make a most attractive and serviceable mount.
The Motor Cycle, November 5th, 1914.
