Royal Enfield 500 TWIN 1949 Workshop Maintenance Manual page 14

ROYAL ENFIELD WORKSHOP MANUAL
pressing it up and down with the fingers. Adjust
the tension so that there is 1/4 in. up and down
movement at the tightest spot.
Re-tighten the locknut on the adjusting screw,
replace the chain cover and replenish with oil.
6. Timing Chain Adjustment
"500 Twin." Before adjusting the tension of
the timing chain, turn the engine until the chain
is in its tightest position and any slack is between
the rear cam sprocket and the timing sprocket on
the engine shaft.
The tension of the timing chain is altered by
moving the quadrant after slackening the nut
which secures it. This rotates the eccentric
spindle on which the chain tensioner jockey
sprocket is mounted. Tightening of the chain is
effected by moving the quadrant to the left.
It is imperative that the quadrant is fitted the
right way round and that the eccentric spindle is
fitted correctly in the quadrant fork. If the chain
tightens when the quadrant is moved to the right,
the tensioner has been wrongly assembled and
may cause damage to the quadrant. (See
diagram.)
In making the adjustment, care must be taken
to see that any backlash in the quadrant is taken
up in the "tightening" directions, i.e. do not make
the chain too tight and then move the quadrant
back slightly, but tighten the chain progressively
TIMING CHAIN ADJUSTMENT SHOWING
TIMING MARKS
" 500 Twin "
Fig. 3
until the correct tension is obtained and then
lock the quadrant. If the chain becomes too tight
during adjustment, slacken it right back and
make the adjustment again.
After the adjustment has been completed and
the quadrant has been locked in position, turn
the engine slowly and check the tension at
frequent intervals to ensure that excessive
tightening does not take place in any one
position.
"Meteor 700." Before adjusting the tension
of the timing chain, turn the engine until the
chain is in its tightest position and any slack is
between the rear cam sprocket and the timing
sprocket on the engine shaft (see Fig. 5).
Slacken the securing bolt on the chain
adjuster and the locknut on the adjusting screw.
Turn the adjusting screw until the correct chain
tension is obtained and tighten the locknut and
securing bolt.
After the adjustment has been completed and
the adjusting arm locked in position, turn the
engine slowly and check the tension at frequent
intervals to ensure that excessive tightening of
the chain does not take place in any one
position.
On some earlier models the chain tensioner
incorporated a spring plunger. This can be
replaced, if necessary, by the present design,
which is interchangeable.
7. Magneto Chain Adjustment
To adjust the magneto chain tension, remove
the timing cover (see Subsection 1), slacken the
three magneto fixing bolts and loosen the bolster
stud nut. Slide the magneto back until the chain
has about 3/16 in. up and down movement, then
tighten the fixing bolts.
Section C1 Page 3