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  5. F236/4R Mk. II OHC Instruction Book 1950
  6. Refitting the Crankpin

This construction makes it necessary to tighten both Crankpin-nuts evenly when fitting, otherwise the Sleeve might be moved on the pin. When re-assembling the pin or fitting a new one, tap the pin carefully into the Flywheel and tighten down the nut only far enough to pull the edge of the Sleeve into light contact with the face of the Flywheel. Always make certain that the two faces are quite clean before fitting. It is immaterial which way round the pin is fitted and as the Sleeve is recessed at both sides there is no need to register any oil hole in the Crankpin with the oil-hole in the Flywheel. Before fitting, however, make sure that the oil passage through the timing-side Mainshaft to the inner face of the Flywheel is quite clear, and also see that there is no restriction in the oil hole in the Crank pin sleeve.

SPECIAL NOTE.

When the Crankpin is fitted it must be located so that the oil hole in the crankpin sleeve which runs through into the roller track is set to face to the rear at 90 degrees from the vertical with the fly wheels set at top dead centre.

Oversize rollers are also usually obtainable. The standard diameter is .1875-in., and there are two oversizes, .0002-in. and .0004-in. oversize respectively. In addition, should the hardened ring in the Connecting rod be worn or pitted, this also may be renewed.

With the Connecting rod mounted with rollers and cage in position on the Crankpin the slightest perceptible vertical play should be allowed with a dry bearing. Should there be slight stiffness this can usually be eliminated by carefully lapping out the ring in the rod or slightly polishing down the Crank-pin sleeve.

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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