JA Purity IV JA Purity IV
JA Purity IV JA Purity IV
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  6. Engine Shaft Shock Absorber

The shock absorber spring, and the splined shock absorber clutch can be removed for inspection or replacement without removing the front half of the primary chaincase and are accessible after removal of the front of the dynamo belt cover, the belt, and the mainshaft nut or shock absorber spring collar (Fig. 7).

fig 007 200dpi

Dismantle the cover as shown, take off the belt and withdraw the split cotter from the mainshaft. Engage top gear and hold the rear brake on whilst the nut is loosened and removed. The spanner A229 is required. A hammer will be needed on the spanner to start the nut.

As the collar unscrews the dynamo pulley flange and pulley, which locate on the collar, will come off with it. The spring and shock absorber clutch will then pull off.

When refitting, grease the splines and shock absorber cam-faces liberally and note that the projection on the pulley must engage the slot in the pulley flange, and the projection on the pulley flange must be engaged with one of the slots in the edge of the collar.

Replace the plain washer on the end of the shaft, and fit the collar. Tighten fully, and fit a new split cotter, afterwards spreading out the ends of the cotter

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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