Table 4-2. Troubleshooting (cont)
Test or Inspection
(2) With engine stopped, turn main adjustment needle and idle adjustment needle fully clock.
wise to close.
(3) Turn main adjustment needle three-quarters of a turn counterclockwise, and idle adjust.
ment needle one-half turn counterclockwise. Start engine and run until warm.
(4) Apply load and observe engine exhaust. If exhaust is black, close main adjustment needle.
If engine misfires or seems low in power, open main adjustment needle. Adjust main adjust.
ment needle until engine delivers maximum power with minimum of exhaust smoke.
(5) If engine application has a throttle speed adjustment, regulate idle mixture in a similar
(6) Regulate engine idle rpm by turning idle speed regulating screw clockwise or counter-
clockwise enough to keep the engine running smoothly.
Step 4. Inspect for dirty or damaged spark plug.
Remove, clean, adjust or replace spark plug.
(1) Using figure 4-8 as guide, loosen the connector nut on spark plug end of the cable.
(2) Remove the spark plug from the cylinder head.