Replacing Spark Plugs; Adjusting Governor - Toro 30789 Operator's Manual

Replacing Spark Plugs

Change spark plugs after every 400 operating hours to
assure proper engine performance and reduce exhaust
emission level.
Correct spark plug to use is a Motorcraft–AGSF22C or
AGRF22 or equivalent.
Recommended air gap is .040" (1.016 mm).
Note: The spark plug usually lasts a long time; however,
the plug should be removed and checked whenever the
engine malfunctions.
1. Clean area around spark plugs so foreign matter cannot
fall into cylinder when spark plug is removed.
2. Pull spark plug wires off spark plugs and remove plugs
from cylinder head.
3. Check condition of side electrode, center electrode, and
center electrode insulator to assure there is no damage.
Important A cracked, fouled, dirty or otherwise
malfunctioning spark plug must be replaced. Do not
sand blast, scrape, or clean electrodes by using a wire
brush because grit may eventually release from the plug
and fall into the cylinder. The result is usually a
damaged engine.
4. Set air gap between center and side of electrodes at
.040" (1.016 mm). Install correctly gapped spark plug
and tighten plug to 11–15 ft–lb. If torque wrench is not
used, tighten plug firmly.
5. Install spark plug wires.

Adjusting Governor

1. With engine shut off, move throttle control to FAST
position and open hood. Check between the throttle arm
and the stop on the carburetor base to make sure there is
1/32" (0.8 mm) gap (Fig. 33). If gap is not correct,
adjust throttle rod (Fig. 33) by turning ball joint ends
until gap is 1/32" (0.8 mm). If gap is correct, proceed to
step 2.
Warning
Engine must be running so final adjustment of the
governor can be performed. To guard against
possible personal injury, engage parking brake
and keep hands, feet, face and other parts of the
body away from fan or other moving parts.
2. Start engine and move throttle to SLOW position.
Allow engine to warm up to normal operating
temperature.
3. Rotate throttle arm closed until it contacts stop
(Fig. 33).
1. 1/32" (0.8 mm)
2. Throttle rod
3. Carburetor idle speed
screw
4. Check idle speed and adjust carburetor idle speed screw
if necessary to attain 1350 + 50 rpm.
5. Release throttle arm, loosen jam nut on governor low
idle speed screw and adjust it to attain 1500 + 100 rpm
(Fig. 33).
6. Slowly move throttle to FAST position until engine
speed reaches 3200 + 100 rpm. Shut off engine. Adjust
high idle stop screw until it contacts speed control lever
(Fig. 34).
Important
Do not over speed the engine because the
transmission could be damaged.
7. Move throttle rapidly from SLOW to FAST. The engine
should not surge. if engine surges, proceed to step 8.
8. Check V–belts from engine to governor pulley and
assure they are tight. If belts are loose, the engine will
surge. If belts are tensioned properly, loosen jam nut
that retains the anti–surge screw (Fig. 34). Rotate screw
clockwise 1/8 turn at a time until surging stops. Should
governor continue to surge, check the following:
Carburetor too rich or too lean.
Binding in throttle linkage.
Governor worn internally.
34
4
1
3
Figure 33
4. Stop
5. Throttle arm
2