John Deere 318 - Manual (Page 332)

3k
Ignition Timing
Check—
For Machines
(S.N. 420001— )
NOTE: Ignition timing is
not adjustable. If a
misfire condition exists,
the flywheel key may
be partially sheared.
This can be verified by
checking the ignition
timing.
M45246 -UN-12JAN90
N
CAUTION: FAILURE TO REMOVE SPARK
PLUGS BEFORE TURNING FLYWHEEL BY
HAND MAY CAUSE ENGINE TO START
RESULTING IN INJURY.
Disconnect and ground spark plug wires.
Remove spark plugs.
NOTE: Terminal (A) is larger in diameter of the
two posts.
Connect a voltmeter or continuity test lamp
between negative (—) coil terminal (A) and
ground.
M45247 -UN-12JAN90
Slowly turn the flywheel clockwise by hand until
the voltmeter reading changes from 1 volt to
approximately 12 volts, or the test lamp goes
out.
For correct timing, one of the flywheel screen
screws (A) should be between the marks (B) on
the blower housing. The marks are at the 11
o’clock position.
To recheck timing, the flywheel must be turned
another complete revolution. Moving the flywheel
back and forth across the timing marks will not
activate the electronic ignition control.
TIMING NOT
CORRECT: Check
flywheel key for
sheared condition, or if
ignition control module
and magnetic trigger
ring are properly
positioned.
3l
Ignition Voltage
Test at TDC Module
PTO switch OFF.
Hydrostatic lever in
N/STOP position.
NOTE: Engaged park
brake required on
machines:
316 (S.N. 596121— )
318 (S.N. 600305— )
420 (S.N. 595881— )
Engage park brake.
Turn key switch to RUN
position.
M37172 -UN-25JAN90
At both sides of TDC
8-pin connectors, check
for voltage at terminal
with pink and orange
wires and terminal with
single pink wire (A). VOLTAGE BOTH
TERMINALS: Pink wire
from TDC connector to
engine connector is
open. Repair or replace
wire as necesary, then
GO TO
Æ
, Group 05.
VOLTAGE ONE
TERMINAL: Repair
connector.
NO VOLTAGE: GO TO
3m
MX,159024025,51-19-16MAY95
MX,159024025,53-19-16MAY95
Electrical System Diagnosis/Ignition Circuit Tests
TM1590 (17MAY95)
240-20-20
316, 318 & 420 Lawn and Garden Tractors
020895
240
20
20