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  5. F40/5R GTP Instruction Book 1951
  6. Lubrication Of Engine

Lubrication Of Engine

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The oil supply is directly controlled automatically by the throttle with which the pump is interconnected. As the throttle is opened more oil is fed to the engine in direct proportion to the speed of the engine and the load upon it. The pump is very carefully set before delivery and should not require any readjustment. If, however, the carburetter is removed or the engine is dismantled it is necessary to see that the control sleeve on the pump is at its lowest position when the throttle is shut and the small nuts on the top of the coupling rod should be adjusted to achieve this. If it is found that an excessive amount of oil is being fed to the engine at low speeds, the pump may be adjusted by pulling out the split pin from the pump adjusting screw which will allow the screw to be turned in the adjusting sleeve.† To decrease the supply turn the adjust­ing screw a quarter turn in a clockwise direction. Only a very slight movement of the adjusting screw will have a considerable effect on the pump, and it is essential, therefore, not to move the adjusting screw more than a quarter turn at any time before checking the results of the adjustment. The split pin must be carefully replaced and the ends opened out. If it is desired temporarily to increase the oil supply this can be done by adjusting the nuts on the rod connecting the pump with the carburetter so that the adjusting sleeve does not reach the bottom when the throttle is shut.

On early three-speed models the oil supply is regulated by means of the knurled-headed screw P11 (see illustration showing engine in section). Full supply is obtained with the screw set four complete turns out from the fully screwed-in position. For normal running, about two turns out will be sufficient, but full supply should be given for all full throttle work.

If the engine has been flooded with oil, smoking will continue for some time. It is possible that an engine may be running dry yet smoke will issue from the exhaust because of the unburnt oil left in the silencers by the previous excessive over-oiling. It is necessary to allow for this possibility when adjusting the oil regulator.

†In practice such an adjustment is seldom necessary. Before altering the setting make sure the excess oiling is not due to the control sticking and thus increasing the supply.

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  • Velocette Documents
    • GTP Manuals
      • F40/5R GTP Instruction Book 1951
    • KSS, KTS Manuals
      • F236/4R Mk. II OHC Instruction Book 1950
      • F42/3R OHC Models 1925-1931 Instruction Book
    • MAC Manuals
      • F469/4R MAC Service Guide 1965
      • F466/2R MAC Owner's Handbook 1955
      • F50/7R MAC Rigid Frame Service Manual 1955
      • F50/4R Supplement
    • MOV and MAC
      • F131-3R Instruction Book 1937
    • MSS Manuals
      • F477 Owners Handbook 1954
    • Venom, Viper, MSS
      • F485/1R Owner's Handbook 1956
      • F484/9R Service Guide 1967
      • F484/11R Service Guide 1971
    • Valiant Manuals
      • F62-1R Service Manual