TECHNICAL DATA
Engine Number—on top of crankcase below cylinder.
Frame Number—at top of steering head tube.
Engine:
Capacity
. .
. .
. .
. .
. .
. .
. .
. .
. .
Cylinder bore
. .
. .
. .
. .
. .
. .
. .
. .
Stroke
. .
. .
. .
. .
. .
. .
. .
. .
. .
Compression ratio . .
. .
. .
. .
. .
. .
. .
. .
Piston ring gap
. .
. .
. .
. .
. .
. .
minimum
maximum
Sparking plug
. .
. .
. .
. .
. .
. .
. .
. .
Plug points gap
. .
. .
. .
. .
. .
. .
minimum
maximum
Contact breaker points gap
. .
. .
. .
. .
. .
. .
Ignition timing (fixed) . .
. .
. .
. .
. .
. .
. .
173 c.c.
61·5 mm.
58 mm.
10/1
·009 in.
·013 in.
N4
·020 in.
·025 in.
·012 in.
18 degrees
(before
T.D.C.)
Transmission:
Gear ratios . .
. .
. .
. .
. .
. . top
third
second
first
Supreme,
Sports
6·58
8·55
12·04
18·68
Bushman
8·1
10·5
14·8
23·0
Clutch—friction plates . .
. .
. .
. .
. .
4
4
Chain size and pitch
front
⅜
× ·250 in.
. .
. .
. .
. .
. .
rear ½ × ·335 in. roller
. .
. .
. .
. .
50 pitches
120 pitches
50 pitches
128 pitches
Teeth on: engine sprocket
. .
. .
. .
. .
17
17
gearbox sprocket
. .
. .
. .
. .
clutch sprocket. .
. .
. .
. .
. .
rear chainwheel
. .
. .
. .
. .
16
38
47
16
38
58
Capacities:
Fuel tank
. .
. .
. .
. .
. .
. .
. .
. .
. .
Petroil mixture
. .
. .
. .
. .
. .
. .
. .
. .
Gearbox
. .
. .
. .
. .
. .
. .
. .
. .
. .
Front forks . .
. .
. .
. .
. .
. .
. .
. .
. .
1
⅞
gallons
See pages
12 and 22
1 pint
⅛
pint
(Supreme),
1
⁄
6
pint
(Sports and
Bushman)
each leg
5
