About The Site
Identification Marks.
| Engine number and Prefix letters MAC : | Stamped on left-hand side of crankcase below the cylinder base flange. (Always include serial letters when quoting the identification number.) See Fig. 7. |
| Frame Number : | Prefix letters RS. Stamped on right-hand side of saddle front mounting lug. |
| Gearbox Number : | Prefix No. 11/ or 14/. Stamped on right-hand side of housing at top. |
Engine.
| Capacity (Swept Volume) : | 349 cubic centimetres. 21.289 cubic. in. |
| Bore and stroke : | 68 m.m. x 96 m.m. 2.677 x 3.779-in. |
| Actual Bore diameter : | 2.677-in. |
| Tappet clearance (Cold). For running. | Inlet .005-in. |
| Exhaust .005-in. | |
| Tappet clearance (Cold). For setting timing. | Inlet .030-in. to |
| Exhaust .035-in. |
Note.-Follow instructions on page 26 before checking or resetting tappet clearances.
| Ignition Timing. | 38 ° before top dead centre, fully advanced (Points open .0015-in.) |
Valve Timing. (When checked with .030-in. to .035-in. Tappet clearances.)
Note.-Readjust to running clearances after checking.
|
Cam |
Cam |
Cam |
||
|
M17/5 |
M17/4 |
M17/7 |
||
| Inlet opens | 30° | 50° | 19° | Before top dead centre. |
| Inlet closes | 60° | 60° | 49° | After bottom dead centre. |
| Exhaust opens | 60° | 70° | 49° | Before bottom dead centre. |
| Exhaust closes | 30° | 40° | 19° | After top dead centre. |
| Compression ratio : | 6.75 to one. |
| Compression space : | 60-62 c.c. |
| Valve spring free length : | Outer : 2 9/64 (2.1406) inches. |
| Inner : 1 15/16 (1.9375) inches. |
| End gap-Compression rings : | .0085-in. to .0115-in. |
Stocked .020-in. .040-in .060-in oversize |
| End gap. Oil control ring : | .0105 to .0135-in. | |
| Side clearance : Compression rings : | .0005 to .0025-in. | |
| Side clearance. Oil control ring : | .0025 to .0045-in. |
Gudgeon-pin. .624-in. diameter (± .0001-in.) Stocked .001-in. oversize.
Small end bush. .625-in. inside diameter ( +.0005-in. - .0002-in.)
Big end. Crankpin roller track diameter 1.374-in. 16 rollers-caged. 3/16-in. diameter by 9/16-in. long. Stocked .0002-in. and .0004-in. oversize.
| Amal. Type 276EY /1AT. 15/16-in. choke diameter. | |
| Throttle valve. 6/4. | |
| Needle jet size 107 (No. 4/061). | |
| Main jet 130. | |
| Jet needle position 3. | |
| Monobloc. Type 376/48. | |
| Throttle valve 3½. | |
| Needle jet 105. | |
| Main jet 200. | |
| Pilot jet 25. | |
| Needle position 3. | |
Magneto. Lucas type K1F. Anti-clockwise rotation. Fixed ignition with automatic advance and retard unit type JY16A.
Dynamo. Miller type DVR. 6-volt. Anti-clockwise rotation with automatic voltage regulation.
Lighting Bulbs. Head lamp : 24-W x 24W 6-volt S.B.C. Cap. or 30 X 24W Double Filament Bifocal Pre-focussed type.
Parking : 6-volt, 3w. S.C.C. Cap. or 6-volt, 3W. M.E.S. Cap.
Tail : 6-volt, 6W. S.C.C. Cap.
Stoplight : 6-volt, 18 x 6W. Offset pin Stoplight type.
Battery. 6-volt. 13 A.H. Varley, Exide, or Lucas.
Gearbox. 4-speed. Foot controlled.
Ratios (overall) with 21 tooth final drive sprocket : First, 14 to 1 ; Second, 9.6 to 1 ; Third, 7.3 to 1 ; Fourth (top) 5.5 to 1.
Sprockets. ½-in. pitch x .305-in.
Engine 21 teeth. Clutch, 44 teeth. Final drive, 21 teeth. Rear wheel, 55 teeth.
Chains.
Primary. ½-in. pitch. .305-in. width. .335-in. roller diameter. 67 pitches.
Rear. ½-in. pitch. .305-in. width. .335-in. roller diameter. 124 pitches.
Wheels. Rims : Front, WM2 x 19-in. Rear, WM2 x 19-in.
Spokes :
Front—Brake side. 61-in. x 10 SWG. 18 off.
Front—Left side. 71-in. x 10 SWG. 18 off.
Rear —Brake side. 71-in. X 8 /10 SWG. 20 off.
Rear —Right side. 71-in. x 8 /10 SWG. 20 off.
Tyres. Front, 19-in. X 3.25-in. Rear, 19-in. X 3.25-in.
Tyre Pressures. Minimum solo : Front, 16 lbs. per sq. in. (1.1 atm.) Rear; 18 lbs. per sq. in. (1.2 atm.)
For pressure chart see page 85.
Capacities.
Petrol tank : 3 Imperial gallons. 3.6 U.S. gallons. 13.6 litres.
Oil tank :½ Imperial gallon. .6 U.S. gallon. 2.27 litres.
Gearbox :½ Imperial Pint. .6 U.S. Pint. .28 litres.
Front fork : 1 Imperial Pint. .15 U.S. pint. 71 cu. cent. per strut.
Sparking Plug.
14 m.m. diameter. 18 m.m. (extra long) reach.
Suitable types : KLG FE70. Champion NAB. Lodge HLN.
Dimensions.
| Wheel base (In normal loaded position) | 53¾-in. - 136.5-cms |
| Ground clearance (In normal loaded position) | 5½-in. - 14-cms. |
| Saddle height (In normal loaded position) | 30½-in. - 77.5-cms. |
| Overall width | 27.1-in. - 70-cms. |
| Overall length | 7 feet - 213-cms. |
| Weight unladen. | 355-lbs. - 161 kgs. |
Recommended Lubricants
|
B.P. |
Duckhams |
Mobiloil |
Shell |
Wakefield |
|
|
Engine : Summer (Ambient temperatures above 60° Fahrenheit) |
Visco-Static* Energol ' 40 ' |
Q20/50* or NOL ' Forty ' |
Mobiloil Special* or Mobiloil B.B. |
X100 10W/30* or X100 40 |
Castrol XXL |
|
Engine : Winter (Ambient temperature below 60° Fahreheit) |
Visco-Static* Energol ' 30 ' |
Q20/50* or NOL ' Thirty ' |
Mobiloil Special* or Mobiloil A |
X100 10W/30* or X100 30 |
Castrol XL |
| Gearbox |
Energol ' 40 ' |
NOL ' Forty ' |
Mobiloil B.B. |
X100 40 |
Castrol XXL |
|
Front Fork |
Energol ' 20 ' |
NOL ' Twenty ' |
Mobiloil Arctic |
.X100 20/20W |
Castrolite |
|
Wheel Hubs |
Energrease C3 |
H.B.B. Grease |
Mobil MP |
Retinax A or Retinax H |
Castrolease |
|
Primary Chain |
Energol 40 |
NOL ' Forty ' |
Mobiloil B.B. |
X100 40 |
Castrol XXL |
|
Rear Chain |
Energrease C3G |
Laminoid |
Mobil MP |
Retinax A or Retinax H |
Castrolease Graphited |
|
For Grease Gun |
Energrease C3 |
H.P.G. Grease |
Mobil MP |
Retinax A Or Retinax H |
Castrolease |
|
For Oil Can |
Energol 10 |
NOL ' Ten ' |
Mobil Handy Oil |
Donax A.1 |
' Oilit ' |