B50 General.


          SPECIFICATIONS
          ENGINE TYPE
          OHV
          CYLINDERS
          1
          BORE/STROKE mm
          84 X 90
          CAPACITY cm3
          499
          DRY WEIGHT KG
          141
          BHP
          34


      Engine: Light alloy cylinder head, alloy barrel with liner, weight: 39 kg.
      Needle roller big end bearings, three main bearings.
      Comp ratio: 10:1.

      Carburettor: SS & T Amal R930/62 ( MX 1971-72 R932/18,1973 R932/28 ) .
      NEEDLE JET: SS & T 200 ( MX 1971-72 250 1973 180/250 ) MAIN JET 106
      THROTTLE: SS & T 3 1/2 ( MX 1971-72 3, 1973 3 1/2 )

      Valve clearances
      Intake: 0,20 mm ( 0,008 in ).
      Exhaust: 0,25 mm ( 0,010 in ).

      Gearbox: Four speeds. Multiplate clutch with bonded composite segments and built-in transmission shock absorber.
      Gearbox Ratios.
      First: 2:65.
      Second: 1:64.
      Third: 1:24.
      Top: 1:00.
      Capacities
      Gearbox: 280 cm3 (1/2 pint UK, 5/8 pint USA )
      Primary Chaincase: 140 cm3 (1/4 pint UK, 1/3 pint USA )

      Brakes: Front 8" twin leading shoe drum brake with individual snail cam shoe adjustment.
      Rear 7" brake drum with floating cams.

      Electrical: 12 volt ignition system. Crankshaft mounted alternator.
      (Lucas RM21 115 watt)
      Spark plug: N4 (MX N3).
      Spark timing, degrees fully advanced: 30

      Frame: Welded frame with large diameter top tube for strength. Top tube doubles as oil container (OIF). Roller steering head bearings. Needle bearing swinging arm with quadrant adjustment for rear chain.
      Chain sizes: Front: 3/8 pitch (duplex). Rear: 5/8 pitch X 1/4 Wide.

      Dimensions B50SS and B50T

      Wheelbase:             1372mm (54,0 in).
      Ground clearance: 178mm (7,0 in). B50T 190mm (7,5 in).
      Seat height:             813mm (32,0 in).
      Overall width:         737mm (29,0 in).
      Overall length:       2159mm (85,0 in).
      Overall height:       1105mm (43,5 in).
      Dry weight:             141 Kg (310,0 lbs). B50T 135 Kg (298,0 lbs).



      The 1972 B50 MX was equipped, different from the 1971 model:
      ET ignition with 60% of the stator cut off to save weight.




      Updated 22:59 2004-02-08
      © Rickard Nebrér