Royal Enfield METEOR MINOR STANDARD 1958 Workshop Maintenance Manual page 11

that firing occurs when the piston is 1/32 in.
before top dead centre, which is equivalent to
3/8 in. to 7/16 in. when fully advanced.
To set the ignition timing, put the gearbox in
top gear and turn the engine by means of the
back wheel until the left-hand piston is 1/32 in.
before top dead centre on the compression
stroke, i.e., with both valves closed. The position
of the piston can be determined by means of a
wire or rod inserted in the sparking plug hole.
Slacken the clamp bolt which holds the
distributor body to the housing at the back of the
timing cover and turn the distributor body until
the contact points are just opening, then
retighten the clamp bolt.
Check the timing again and also the
maximum opening of the points and check that
the rotor arm, when replaced, points towards the
segments connected to the left-hand sparking
plug lead.
There are several methods of determining the
point at which the contacts open:
(1) Switch on the ignition. Looking on the
left side of the engine, rotate the cam in a
clockwise direction (or the housing in a
counter-clockwise direction) until the warning
light in the ammeter lights up or until the
ammeter needle indicates a discharge. Continue
to rotate the cam (or housing) slowly until the
warning light goes out or until the ammeter
needle returns to zero, indicating that the points
have opened.
(2) Remove the sparking plug cap from the
lead and tuck the lead between the fins of the
cylinder. Rotate the cam (or housing) and a
spark will be seen at the instant the points open.
(3) Insert a piece of thin tissue paper between
the points of the contact breaker and turn the
cam (or housing) until the paper can just be
pulled out.
If the timing drive has been dismantled or the
distributor removed for any reason, turn the
engine until the left-hand piston is 1/32 in.
before top dead centre on the compression
stroke and clamp the distributor housing so that
the name on it is roughly horizontal.
Replace the chain with the cam in such a
position that the contacts are just opening (or as
near as possible to this position) with the rotor
arm, if replaced, pointing towards the lead to the
lefthand sparking plug.
Make the final adjustment by slackening the
clamp bolt and rotating the distributor body as
described above.
5. Primary Chain Adjustment
The tension of the primary chain can be
checked through the inspection cover in the
primary chaincase and, should it require
adjustment, access to the adjuster is gained by
removing the chaincase cover, which is held in
position by a single nut.
Section C13 Page 2
PRIMARY CHAIN ADJUSTMENT
Before removing the nut, place a tray under the
engine to catch the oil from the chaincase.
Beneath the bottom run of the chain is a
curved slipper on which the chain rests and
which may be raised or lowered by turning the
adjusting screw after having first slackened the
locknut.
A rubber button is fitted to the end of the
adjusting screw to prevent the transmission of
chain noise to the chaincase and this is held
against the chaincase by a hairpin spring, which
prevents it from bouncing.
Do not adjust the chain to be dead tight but
rotate the engine slowly and, while doing so, test
the tension of the top run of the chain by
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.
Retighten the locknut on the adjusting screw,
replace the chain cover and replenish with oil.
6. Timing Chain Adjustment
Before adjusting the tension of the timing
chain turn the engine until the chain is in its
tightest position, checking the chain between all
sprockets.
Adjust the tension so that there is 1/4 in.
movement of the chain.
The tension of the timing chain is altered by
moving the quadrant after slackening the nut A
which secures it (see Fig. 2). This rotates the
eccentric spindle on which the chain tensioner
Fig. 1