Instruction manual

TO REMOVE AND REPLACE THE OIL PUMP PLUNGER

Remove

Lower end of rocker box oil feed pipe by unscrewing union nut.

Both oil pump end caps.

Oil pump plunger guide screw with pin. (See Illustration 12.)

Oil pump plunger, by pushing at front and extracting from rear end of its housing.

Replace by :

Reversing above procedure.

NOTE—Remember there is a paper washer under each oil pump end cap and, when

fitting a new paper washer to the front cap, ensure the oil passage in the

front cap is not obstructed by the paper washer.

Make certain that the guide screw pin is correctly located in its groove (cut in

the plunger) before tightening down. NOTE :—The guide screw pin is in-

serted in the screw relieved end first. Do not revolve the engine until quite

certain that the guide screw pin is properly located, otherwise damage is

inevitable.

OVERSIZE PARTS AND RE-BORING CYLINDER BARREL

Pistons and rings, .020" and .040” larger than standard, are available. These degrees

of oversize make it essential for the cylinder barrel to be re-bored to accommodate them.

We can provide that service at prices quoted In the Spares List.

On the 350 c.c. the cylinder standard bore is 2.7187 ± .0005". The 500 c.c. cylinder

standard bore is 3.250 ± .0005".

When the wear at the top of the barrel reaches .008" the barrel should be bored out

.020" oversize and a new oversize piston and rings fitted.

Crankpin rollers .001" larger than standard can be supplied. We recommend only

skilled mechanics should fit these because it is almost general that the big-end journals

and sleeves require " lapping " to ensure a correct fit.

REMOVING SPARKING PLUG

Always exercise the greatest care to avoid thread seizure when removing a sparking

plug. If any resistance is felt, apply paraffin. Before replacing plug, it is desirable to

coat the thread with " Oil Dag" or Graphite paste. This will guard against seizure

upon subsequent removal.

WHEN IN DOUBT REGARDING THE NAMES AND PART

NUMBERS OF THE PARTS YOU REQUIRE, PLEASE SEND

THE OLD PARTS TO SERVE AS PATTERNS.