Royal Enfield 350 BULLET 1949, Workshop Maintenance Manual

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ROYAL ENFIELD WORKSHOP MANUAL
SECTION D2
Service Operations with Engine
Removed
“ 350 and 500 Bullet” Engines
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 control cable from the
magdyno.
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 out the engine.
2. Removal of the Gear Box
Remove the primary chain case, engine
sprocket and clutch (see Section C.2, Subsection
24).
Remove four 3/8 in. nuts and the gearbox can
then be withdrawn from the engine.
3. Dismantling the Crankcase
350 + 500 c.c. Engine . Drain the oil tank by
removing the drain plug.
Having removed the engine from the frame as
described in Subsection 1, dismantle the cylinder
head, barrel, piston, timing gear, magdyno, etc., as
described in Section C.2.
Remove the nuts on the driving side of the
engine from four fixed studs at the rear of the
crankcase.
Remove six studs passing through the
crankcase.
The two halves of the crankcase can then be
separated.
The timing side outer roller race and the
bronze bush will remain in the timing side half of
the crankcase.
The driving side ball race and the driving side
outer roller race will remain in the driving side
half of the crankcase.
The driving side inner roller race and the
inner distance piece will remain on the engine
shaft.
The flywheel assembly may be difficult to
remove from the driving side of the crankcase
owing to the shaft being a tight fit in the inner
race of the ball bearings. This is particularly
likely in the earlier engines with two ball
bearings. In this case push the shaft out of the
bearings using crankshaft extractor E.5121.
4. Main Bearings
To remove the Outer roller race(s) (or inner
ball race on earlier 350 Bullet engines) from the
crankcase halves, heat to 100°C or more and
drop the half case sharply on a flat block of
wood or bench, when the race(s) will drop out,
together with the distance piece in the case of
the driving side and the thrust washer in the case
of the timing side.
Remove the circlip from the driving side
crankcase and re-heat to remove the second ball
race.
To replace the bearings, heat the crankcase
and press in the races in the following order
Driving Side. Use Special Tool No. 4817.
Small steel washer.
Cork oil-retaining washer
Large steel washer.
Ball bearing complete.
Circlip.
Outer distance piece*
Outer roller race*
* On 500 and later 350
engines. (On early 350
engines a distance piece and
inner ball race)
Timing Side. Use Special Tool No. 4816.
Steel thrust washer. Outer
roller race.
Care must be taken to see that the lead on the
outside of the outer roller race enters the case
first to make sure that it is square with the
housing.
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
350 c.c. Engine. The flywheel assembly con-
sists of the crankshaft and the connecting rod.
To dismantle the crankshaft remove the set
screws securing the crankpin nuts.
Holding the crankshaft in a Special Jig, No.
E.2775, remove the crankpin 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 crankpin with a hand press.
The connecting rod can then be removed.
Turn the crankshaft over in the jig and repeat
with the other side if necessary.
To remove the main shafts, remove the set
screws from the shaft nuts and unscrew the nut.
Drive the shafts out with a hammer and drift.
To replace the main shafts, reverse the above
process, making sure that the keys are a good fit.
To re-assemble the crankshaft, press the
crankpin into the timing side flywheel, making
sure that the oil hole is in the correct position
and that the thrust washer is facing the right way,
i.e., with the chamfer away from the flywheel.
Test the oil passages with an air line or oil
gun to make sure that they are clear.
Smear oil over crankpin and floating bush.
Put the floating bush over the crankpin.
Put the connecting rod over the floating bush.
Place the other thrust washer over the
crankpin, also with the chamfer away from the
flywheel.
Press the driving side flywheel on.
Put the flywheel in the assembly jig E.2775,
to ensure that the flywheels and shafts are in line
and replace the nuts, tighten securely and refit
the set screws.
Test the oil passages again to ensure that they
are clear.
If the same crankpin has been put back, it will
be necessary to drill out the grub screw, in order
to clean the oil passages after which a new grub
screw must be fitted.
Mount the crankshaft between centres and
true up to .0005 in. on either side of the shafts.
If the readings for the two shafts are high on
opposite sides, the error can be corrected by
gently tapping either or both of the flywheels.
If the readings are high on the same side of
the two shafts, it is probably due to dirt or
foreign matter in the joints and the crankshaft
should be dismantled again, carefully examined
and cleaned and re-assembled.
500 c.c. Engine. The flywheel assembly con-
sists of the crankshaft and the connecting rod.
To dismantle the crankshaft remove the set
screws securing the crankpin nuts.
Holding the crankshaft in a special jig, No.
E.2775, remove the crankpin 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 crankpin with a hand press.
The connecting rod can then be removed.
Turn the crankshaft over in the jig and repeat
with the other side if necessary.
To remove the timing side main shaft, take
the set screw from the shaft nut and unscrew the
nut. Drive the shaft out with a hammer and drift.
To replace the timing side shaft, reverse the
above process, making sure that the key is a good
fit and that the nut is tightened securely by means
of a box spanner with a 12 in. tommy bar.
The driving shaft has no nut but is secured by
tightening the sprocket nut after the assembly of
the engine. It should be pressed in and out with a
hand press or a hammer and drift. If the latter is
used care must be taken not to damage the
centre.
To re-assemble the crankshaft, press the
crankpin into the timing side flywheel, making
sure that the oil hole is in the correct position and
that the thrust washer is facing the right way, i.e.,
with chamfer away from the flywheel.
Test the oil passages with an air line or oil
gun to make sure that they are clear.
Put the floating bush over the crankpin.
Put the connecting rod over the floating bush.
Place the other thrust washer over the
crankpin, also with the chamfer away from the
flywheel.
Press the driving side flywheel on.
Put the flywheel in the assembly jig, E.2775,
to ensure that the flywheels and shafts are in line
and replace the nuts, tighten securely and refit
the set screws.
Test the oil passages again to ensure that they
are clear.
If the same crank pin has been put back, it
will be necessary to drill out the grub screw, in
order to clean the oil passages after which a new
grub screw must be fitted.
Section D2 Page 2
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