Adjusting The Carburetor And Speed Control; Replacing The Spark Plugs - Toro Greensmaster
3150 Operator's Manual

3. Pull firmly on the choke cable until the choke butterfly
is completely closed, then tighten the cable clamp screw
(Fig. 45).
Adjusting the Carburetor and
Speed Control
Important Before the carburetor and speed control are
adjusted, the throttle and choke controls must be adjusted
properly.
Warning
The engine must be running during adjustment of
the carburetor and speed control. Contact with
moving parts or hot surfaces may cause personal
injury.
• Shift into neutral and engage the parking brake
before performing this procedure.
• Keep hands, feet, clothing, and other body parts
away from the cutting blades, rotating parts, the
muffler, and other hot surfaces.
1. Start the engine and let it run at half throttle for
approximately five minutes to warm up.
2. Move the throttle control to the Slow setting. Adjust the
idle stop screw counterclockwise until it no longer
contacts the throttle lever.
3. Bend the governed idle spring anchor tang (Fig. 46) to
attain an idle speed of 1625±50 RPM. Check the speed
with a tachometer.
2
1
Figure 46
Shown with Air Cleaner Removed
1. Governed idle spring
anchor tang
2. High speed spring anchor
tang
32
4. Adjust the idle stop screw clockwise until the idle speed
is an additional 25 to 50 RPM over the idle speed set in
step 3.
5. Move the throttle control to the Fast position. Bend the
high speed spring anchor tang (Fig. 46) to attain a high
speed of 2850±50 RPM.

Replacing the Spark Plugs

Replace the spark plugs after every 800 operating hours.
The recommended air gap is 0.030 in. (0.76 mm)
The correct spark plug to use is a Champion RC 14YC.
Note: The spark plug usually lasts a long time; however,
the plug should be removed and checked whenever the
engine malfunctions.
1. Clean the area around the spark plugs so foreign matter
cannot fall into the cylinder when the spark plug is
removed.
2. Pull the spark plug wires off of the spark plugs and
remove the plugs from the cylinder head.
3. Check the condition of the side electrode, center
electrode, and center electrode insulator to ensure that
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 the air gap between the center and side of the
electrodes at 0.030 in. (0.76 mm) (Fig. 47) Install the
correctly gapped spark plug w/gasket seal, and tighten
the plug to 200 in.-lb. (23 N⋅m). If a torque wrench is
not used, tighten the plug firmly.
Figure 47
0.030 in.
(0.76 mm)