Royal Enfield CO Workshop Maintenance Manual page 5

ROYAL ENFIELD 350cc O.H.V. WORKSHOP MANUAL
ROYAL ENFIELD 350 c.c. O.H.V. MOTOR CYCLE
ENGINE.
Cubic Capacity ... ...
Stroke ... ... ...
Bore ... ... ...
(Rebore to •015 in. when wear exceeds .008 in. and again to
.030 in. after further .008 in. wear.)
Compression Ratio ................... ... ....... ... ........ ... ....... ...5.3/4 to 1
Piston Diameter:
Bottom of Skirt
Fore and Aft
Sides ....... ... ....... ... .... 2.740in. ± .00025 in.
Top of Skirt
Fore and Aft
Sides ....... ... ....... ... .... 2.737in. ± .00025 in.
Top Lands ...................... ... .... 2.7285 in. ± .0005 in.
Piston Ring Dimensions-
Width-Plain Rings
Scraper Ring
Radial Thickness .......... ...
Gap when in unworn cyl.
Clearance in grooves .......................................... ........ .
Oversize Pistons and Rings available.
Piston Boss Internal Diameter ............. ..
Gudgeon Pin Diameter ............. ... ....... ..
Small End Bush Internal Diameter
(fine bored or reamered after fitting)
Big End Bush Internal diameter
(ground after fitting) ........................ ... .... 1.625 in. ± .00025 in.
Crank Pin Diameter .................. ... ....... ... 1.249 in. – 1.24875 in.
Main Bearing Outer Race inside diameter
(before fitting) ............ ... ....... ... ...... ..
Timing Side Bush inside diameter
(reamered after fitting)
Driving Side Shaft Diameter
Timing Side Shaft Diameter
Roller Diameter .............. ... ....... ... ...... .
(Graded to nearest .0001 in. and selective assembly used.)
Rocker Bearing inside diameter
Rocker Diameter ............ ... ....... ... ...... ...
Valve Guide inside diameter (before fitting)
Valve Stem Diameter-Inlet .................. ...
Exhaust ................................................. ...
Valve Tappet Clearance (with cold engine)
Valve Timing at .005 in. tappet clearance
Exhaust opens
Exhaust closes
Valve Spring Free Length (outer and inner)
(Renew valve spring when free length is reduced by 1/8 in.)
Cam Bush inside diameter (reamered
after fitting) ................ ... ....... ... ....... ...
Idler Pinion Bush inside diameter (reamered
after fitting) .................... ... ....... ... ....... ...
Cam Spindle .................. ... ....... ... ....... ...
Idler Pinion Spindle .. ....... ... ....... ... .49925 in. - .49825 in.
DATA
... ... ... ... 346 c.c.
... ... ... ... 90 m.m.
... ... ... ... 70 m.m.
(2.751 in. ± .00025 in.)
... .... 2.748in. ± .00025 in.
... .... 2.745 in. ± .00025 in.
... ........... ........ ... ....1/16 in.
... ........... ........ ... ....5/32 in.
.119 in. ± .004 in.
.011 in. to .015 in.
.003 in.
.7500 in. - .7495 in.
.7500 in. - .7495 in.
.7507 in. - .7505 in.
1.3752 in. – 1.3750 in.
... ...... ... .877 in. - .875 in.
... ...... ... .8750 in. - .8745 in.
... ...... ... .8750 in. - .8745 in.
.2500 in. - .2490 in.
.6255 in. - .6250 in
.6240 in. - .6235 in.
.3447 in. - .3437 in.
.3435 in. - .3425 in.
.3415 in. - .3405 in.
Inlet .002 in.
Exhaust .004 in.
75° before b.d.c.
35° after t.d.c.
Inlet opens 30° before t.d.c.
Inlet closes 60° after b.d.c.
1.3/4 in.
.6255 in. - .6250 in.
.502 in. - .501 in.
.6245 in. - .6235 in.
TRANSMISSION.
Sprockets-Engine ...................... ... ... 19 T.
Clutch ..................... ... ... 42 T.
Countershaft
Rear Wheel ............. ... ... 46 T.
Chains-Front ... ...
Rear ... ...
Chain Adjustment-Front
Rear
Gear Ratios First
Second
Third
Top .............. ... ....... ... ....... ... ........... 5.65 to 1
Clutch Thrust Rod Length
Clearance in Clutch Control
Gear Box Ball Bearings-
Large Internal Dia. 30 m.m.
External Dia. 62 m.m.
Width
Small Internal Dia.
External Dia. 1
Width
Gear Box Layshaft Bearings (reamered after fitting)
Left side Internal Dia. 1.001 in. – 1.000 in.
Right side Internal Dia. .7195 in. – .7185 in.
Kickstarter Shaft Bearing Internal Dia.
FRAME AND WHEELS.
Wheel Hub Ball Races
Front-Internal Diameter
External Diameter
Width...
Rear-Internal Diameter
External Diameter
Width...
Wheel Rim Size ... W.M.2-19in. for 3.25-19 in. Tyre.
Front and rear rims interchangeable.
Wheel Spokes
Front, near side ... ... 6
Front, off side ............. ... ... 8
Rear, near side ........... ... ... 7
Rear, off side .............. ... ... 8
Spoke lengths measured under head.
Nipples are .140 in. dia. x 40 T.P.I.
Cush Drive, allowable free movement at wheel rim when rear
1
brake is on ... ... ... / in. to 1 in.
2
Steering Head Balls ... ...
1
/ in. P. X .305 in. W,
2
1
/ in. P. X .305 in. W.
2
5
... ... 18 T. / in. P. X .380 in. W.
8
5
/ in. P. X .380 in. W.
8
1
74 pitches / in. P. X .305 in. W.
2
5
89 pitches / in. P. X .380 in. W.
8
1
... ....... ... ....... ... ......... / in. slack.
4
1
... ....... ... ....... ... ......... / in. slack.
2
... ....... ... ....... ... ........... 18.6 to 1
... ....... ... ....... ... ........... 11.2 to 1
... ....... ... ....... ... ........... 7.9 to 1
... ....... ... ....... ... . long part 9
short part 1
... ....... ... ....... ... ....... ... ......
16 m.m.
5
/ in.
8
13
/ in.
16
5
/ in.
8
1.1255 in. – 1.1250 in.
12 m.m.
37 m.m.
... ... 12 m.m.
5
/ in.
8
13
1 / in.
16
5
... ... / in.
8
1
/ in. long 8-10g butted.
2
3
/ in. long 8-10g butted.
4
3
/ in. long 8-10g butted.
4
1
/ in. long 8-10g butted.
2
1
/ in. dia. 38 to set (19 each race).
4
Page 5
3
/ in.
8
7
/ in.
8
1
/ in.
16