MASSEY FERGUSON MF 135 Operator's Manual page 50

Spark
Plugs
(See
Fig.
58)
e
Remove the spark plugs every 100
hours for inspection, cleaning and re-set-
ing.
To service spark plugs on gasoline
model Tractors :
a. Remove heat shield.
b. Clean debris from around the
spark plugs.
c. Remove spark plugs with 3/8"
drive 13/16" plug socket.
Check the plug electrodes for wear, and
the porcelain for cracks.
If
the porcelain is
cracked, a new plug must be installed. The
electrodes should be cleaned, preferably by
sandblasting and the gap reset to 0. 025
inch.
NOTE: When resetting this gap
NEVER bend the center electrode.
Always bend the ground or side
electrode, to adjust the gap.
When plugs are installed, a serviceable
gasket should be used and the gasket seat
checked to ensure it is clean. The gasket
is required to dissipate heat from the plug
to help ensure longer life and greater effi-
ciency. Tighten plugs to 32-38 ft. -lbs. tor-
que. Spark plugs should be replaced every
300 operating hours for maximum perform-
ance and fuel economy. Install Champion
N12Y or Massey-Ferguson spark plugs.
The N12Y is a long reach plug which is installed
in all AG3.152 engines from Serial No. 15061 A and
up. When replacing plugs, replace with the same
type.
Fig. 60 - Ignition System - Gasoline
Distributor
(See
Fig.
60)
e
It is impossible to obtain economical
and satisfactory engine performance if the
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