Matchless G2CS Instruction Book page 19

The valve guides and the needle adjusting screw are also shown withdrawn
1
PLAIN HOLE, FOR O I L FEED TO INLET
VALVE.
1 TAPPED HOLE, TO
CARBURETTER RETAINING STUD.
3 INLET PORT.
4
TAPPED HOLE, TO
CARBURETTER RETAINING STUD.
HOLE. TO ACCOMMODATE
5
LOCATING VALVE SPRING SEAT.
6 GUIDE, FOR INLET VALVE,
7 TAPPED HOLE. FOR SPARKING PLUG.
VALVE GRINDING
The grinding is accomplished by smearing a thin layer of fine grinding paste (obtainable
ready for use at any garage) on the valve face and then, after inserting the valve \n the
head, partially revolve, forwards and backwards, while applying light finger pressure to
the head, raising the valve off its seat and turning to another position after every few
movements. (Never revolve the valve continuously in one direction,)
When the abrasive ceases to bite, remove the valve and examine its face.
The grinding may be considered to be satisfactorily completed when a continuous mat
ring is observed on both valve face and seat.
After grinding, all traces of abrasive must be carefully washed off with petrol and a piece
of rag, moistened in petrol, should be pulled through the bore of each valve guide to
remove any abrasive that may have entered.
A holder for the valve, when grinding in the valve, can be supplied. The part number
is 017482.
REPLACING T H E VALVES
A valve spring compressor is required to compress the springs, a special tool which is
inexpensive, can be obtained from dealers, or from our Spare Parts Department. The
application of this tool is shown in illustration 4.
position correctly the valve spring seat—the raised portion on the underside is located
with the depression (5) in cylinder head.
The inlet valve is the larger of the two valves and it is vitally important to locate correctly
the two split collets into the grooves on each valve stem.
Clean the valve guide bores with a piece of clean rag, apply a little oil on the valve stems
and also inside each guide before assembly.
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Illustration 3
ACCOMMODATE
10
I I
ACCOMMODATE
12
D O W E L
13
14
(See illustration 3).
17
17
8 PLAIN HOLE. FOR OIL FEED TO EXHAUST
VALVE.
9 HOLE, TO ACCOMMODATE DOWEL PIN
LOCATING VALVE SPRING SEAT.
GUIDE, FOR EXHAUST VALVE.
CIRCLIP (BOTH GUIDES).
EXHAUST PORT.
NEEDLE SCREW, ADXUSTIMG OIL FEED
TO INLET VALVE.
LOCK N U T . FOR NEEDLE ADJUSTING
SCREW.
Before fitting the valve springs,