TM 5-4310-276-14
Table 4-2. Troubleshooting (cont)
Malfunction
Test or Inspection
Corrective Action
c. Repair or Replacement
(1) Repair or replace the spring tips.
(2) Replace rubber insulators around the springs if torn or damaged.
(3) Replace ignition cable if damaged.
d. Installation
(1) Use figure 4-8 as guide and install ignition cable.
(2) Tighten connector nuts on each end of cable.
6. ENGINE KNOCKS.
Step 1. Check for lean fuel mixture.
Adjust carburetor.
a. Using figure 4-7 as a guide, adjust the carburetor.
b. With engine stopped, turn main adjustment needle and idle adjustment needle fully clockwise
to close.
c. Turn main adjustment needle three-quarters of a turn counterclockwise, and idle adjustment
needle one-half turn counterclockwise. Start engine and run until warm.
d. Apply load and observe engine exhaust. If exhaust is black, close main adjustment needle. If en-
gine misfires or seems low in power, open main adjustment needle. Adjust main adjustment needle until
engine delivers maximum power with minimum of exhaust smoke.
e. If engine application has a throttle speed adjustment, regulate idle mixture in a similar manner.
f. Regulate engine idle rpm by turning idle speed regulating screw clockwise or counterclockwise
enough to keep the engine running smoothly.
Step 2. Check for loose flywheel or pulley.
Tighten the flywheel or pulley.
a. Removal.
(1) See figure 4-16 for removal of belt guard.
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