Section D3 - Royal Enfield SPRING FRAME O.H.V. 250cc CLIPPER 1954 Workshop Maintenance Manual

ROYAL ENFIELD WORKSHOP MANUAL
Service Operations with Engine out of Frame
1. Removal of the Engine from the Frame
Disconnect the battery leads and remove
the battery.
Turn off the petrol and disconnect the petrol
pipe.
Take the slides out of the carburettor.
Remove the air cleaner.
Remove the exhaust pipe.
Disconnect the electric horn leads.
Disconnect the alternator lead connectors
behind the battery carrier.
Disconnect the lead to the contact breaker.
Disconnect the engine steady.
Remove the rear chain.
Remove the footrest bar.
Support the engine on a suitable box or
wood block.
Remove the centre stand and the stand stop.
Remove the front engine plates.
Remove the bolt securing the rear engine
plate to the frame.
Lift the engine and gearbox out.
2. Removal of Gearbox
Remove the primary chain case, engine
sprocket, alternator stator and rotor and clutch.
(See Section C3, Subsection 24.)
Remove two 5/16 in. engine bolts and the
top gearbox bolt.
Slacken the bottom gearbox bolt and the
gearbox can then be lifted out.
3. Dismantling the Crankcase
Drain the oil tank by removing the drainplug.
Having removed the engine from the frame
as described in Subsection 1, dismantle the
cylinder head, barrel, piston, timing gear,
contact breaker housing, etc., as described in
Section C.
Remove the nuts on the driving side of the
engine from two fixed studs at the top of the
crankcase.
Remove the stepped bolt securing the
contact breaker housing strap.
Remove nine studs passing through the
crankcase.
The two halves of the crankcase can then be
separated, the outer races of the main bearings
remaining in the crankcase.

SECTION D3

250 Clipper
4. Main Bearings.
To remove the outer races from the
crankcase, heat the crankcase to 100°C. or more
and drop the halve case sharply on a flat block
of wood or bench, when the race will drop out.
To replace the outer races, heat the case and
press the races in, using Special Tool No. E.
4816 on the timing side and E.5119 on the
driving side.
Care must be taken on the driving side to see
that the oil holes in the bearings come opposite
the two holes in the crankcase.
If it is necessary to replace the rollers, new
ones are available, graded in steps of .0001 in.
from .2490 in. to .2500 in.
5. Replacement of the Cam and Idler
Spindles
To remove the cam spindles heat the
crankcase and tap the spindles out from inside.
To remove the idler spindles heat the
crankcase as before, hold the spindles in a vice
and tap the crankcase lightly with a hide
hammer.
To replace the spindles use special tool No.
E.6462, which is a locating plate for all the
spindles.
Start the spindles in the holes in the
crankcase by tapping them lightly.
Offer the locating plate to the spindles,
making sure that they are all upright. Tap the
plate over the spindles until it touches the
timing chest face, having first made sure that
the latter is quite clean.
Drive the spindles home with a small
hammer (not heavier than 1/2 lb.) and a drift.
Remove the locating plate.
6. Flywheel Assembly
The
crankshaft and connecting rod.
To dismantle the crankshaft remove the set
screws securing the crank pin nuts.
Holding the crankshaft in a special jig, No.
E.2775, remove the crank pin nuts.
Using E.2775, with a pair of steel bars
(about 1 in. x 3/8 in. x 9 in. long) placed across,
press out the crank pin with a hand press.
flywheel assembly consists of
Section D3 Page 1