Tappet Adjustment - Matchless 1949 CLUBMAN G3L Maintenance Manual And Instruction Book

50 TAPPET ADJUSTMENT

The top ends of the two long push rods have screwed extensions. These are locked
in position by nuts, thereby providing tappet adjustment.
The correct tappet clearances, with valves closed and engine cold, is NIL. This means
the push rods should be free enough to revolve and, at the same time, there should be
no appreciable up and down play. (See Para. 48.)
Prepare to adjust tappets by :—
Set piston to T.D.C. See Para. 48.
Remove the three nuts, and fibre washers under them, retaining tappet cover
to rocker box.
Take away cover.
Adjust tappets on all 3S0 and 500 models by:—
With spanners, hold the body C, either valve (Illustration 12) and slacken lock
nut B. Then screw, in or out, the head A until the clearance is nil.
Tighten lock nut B and re-check the clearance.
Treat other valve in like manner.
Finally:—
Check adjustments so that, with no up and down movement, the Iong push
rods are free to revolve when the valves are closed.
Complete adjustment by :—
Replace rocker tappet cover taking care to replace the fibre washer that is under
each retaining nut.
Do not overtighten the nuts because the joint is made with a rubber fillet and
undue pressure is not necessary.
Note :—
The part marked C in Illustration 12 is the top end of the long push rod. It is
threaded and the adjusting screw A screws into it.
In normal conditions tappet adjustment should not be necessary more frequently
than about every five thousand miles or after decarbonising and grinding valves.
If adjustment is found necessary more frequently the cause should be investigated
at once.
Illustration 12
Tappet adjustment.
32