The lubrication has been carefully set before despatch, it should not be necessary to alter this. Do not flood the Engine with Oil because it is a new one. Keep the maximum speed below 40 miles per hour for the first 500 miles. Should it be desired to make an adjustment to the Oil, the adjusting screw K69, (see illustration P.19 ) should be turned clockwise for increasing the amount of oil, but this screw should never be turned more than one quarter of a turn either way at a time, as the adjusting screw is very sensitive. Never cut down the oil supply to a stage when the oil return to the tank ceases or nearly ceases. Never make an adjustment of this screw to stop oil leaks. To cure this, see Curing Oil Leaks.

Should the engine flood with oil, inspect the ball valve in the centre of the crankshaft, K100. This controls in conjunction with the regulating valve, K69, the amount of oil sufficient for the engine. If the valve has dirt on its seating the engine will flood while standing and possibly whilst running. The same may occur if the spring is too weak. Care must be taken when assembling to see that the ball and spring are in their correct positions. It is best done by sticking the ball to the spring with some grease. Place the spring into the crankshaft and tighten up the nut. This nut is L. H. thread and unscrews by turning clockwise. It is advisable to check the oil flowing into the tank after the ball valve has been taken to pieces and reassembled.

It is also possible for this valve to choke with dirt and starve the engine of oil. This will not occur if the oil is put through the strainer when filling up.

To check the circulation of the Oil, remove the Filler Cap on the Oil Tank. If the Oil is circulating satisfactorily, a slightly intermittent stream of oil will be coming through the return Pipe into the Tank when the engine is running.

For purely racing work, Castrol R is recommended for the Engine, but not for the Gearbox or any other part. Care should be exercised in using this, especially in cold weather as it does not circulate freely until the Engine is well warmed up. The Oil Tank must be emptied and cleaned out once in every 1,000 miles. Fill up with fresh oil.

For the lubrication of the parts fitted with grease gun nipples, such as front forks, hubs, brake levers, etc., use Wakefield Ram Gun with Junior Canister of Wakefield's Castrolease medium, or the small grease gun supplied in the tool kit with the above grease. A little oil should be applied to the front chain with an ordinary Oil Can. It can best be done by turning the Engine round with the Kickstarter while the Exhaust Valve is lifted. The back chain should be treated in a similar manner. The above should only be necessary if the pipes from the Rocker Box and the oil tank do not deliver enough to keep the chains lubricated sufficiently

It should be understood that the pipes from Cambox to primary chain cover, and from oil tank to front or rear chains are not fitted as definite chain lubricators. These are drain pipes from the Cambox and vent pipe from the oil tank and are provided to carry away surplus oil and oil vapour to a point where it would be of most use. The chains should therefore be inspected periodically and oiled if necessary.