MTD 21A-120R000 Cultivator User Manual


 
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SECTION 5: MAKING ADJUSTMENTS
WARNING: To prevent serious injury,
never do adjustments, maintenance or
repairs with unit running. Always do
maintenance and repairs on a cool unit.
Disconnect spark plug wire to ensure
the unit will not start.
Wheel Adjustments
To adjust the wheel height, refer to OPERATING
YOUR CULTIVATOR in Section 4.
Carburetor Adjustments
WARNING: If any adjustments are made
to the engine while the engine is running
(e.g. carburetor), keep clear of all moving
parts. Be careful of heated surfaces and
muffler.
The idle speed adjuster of the engine is adjustable
through the air filter/muffler cover. See Figure 22.
NOTE: Careless adjustments can seriously damage
your unit. An authorized service dealer should make
carburetor adjustments.
Check Fuel Mixture
Old and/or improperly mixed fuel is usually the reason
for the unit not running properly. Drain and refill the
tank with fresh, properly mixed fuel prior to making
any adjustments. Refer to OPERATING YOUR CULTI-
VATOR in Section 4.
Clean Air Filter
The condition of the air filter is important to the
operation of the unit. A dirty air filter will restrict air
flow and change the air/fuel mixture. This is often
mistaken for an out of adjustment carburetor. Check
the condition of the air filter before adjusting the idle
speed adjuster. Refer to MAINTAINING YOUR
CULTIVATOR in Section 6.
Adjusting Idle Speed
WARNING: This unit will need to be
running during idle speed adjustment.
Wear protective clothing and observe all
safety instructions to prevent serious
personal injury.
If after checking the fuel mixture and cleaning the
air filter the engine still will not idle, adjust the idle
speed screw as follows.
1. Start the engine and let it run about 2-3 minutes
at a high idle to warm up. Refer to OPERATING
YOUR CULTIVATOR in Section 4.
NOTE: Ensure the tines are not in contact with the
ground when adjusting the idle.
2. Release the throttle control and let the engine
idle. If the engine stops, insert a small phillips or
flat blade screwdriver into the hole in the air fil-
ter/muffler cover. Turn the idle speed screw in,
clockwise, 1/8 of a turn at a time (as needed) until
the engine idles smoothly. See Figure 22.
NOTE: The tines should not rotate when the engine
idles.
3. If the tines rotate when the engine idles, turn the
idle speed screw counterclockwise 1/8 of a turn
at a time (as needed), to reduce idle speed.
Checking the fuel mixture, cleaning the air filter, and
adjusting the idle speed screw should solve most
engine problems.
If not and:
The engine will not idle,
The engine hesitates or stalls on acceleration,
There is a loss of engine power,
have the carburetor adjusted by an authorized service
dealer.
Idle Speed Screw
Figure 22
Engine Specifications
Engine Type … … … … … … …Air-Cooled, 2-Cycle
Displacement … … … … … … … … … … … 31cc
Idle Speed R.P.M. … … … … … … 2,800-3,600 rpm
Operating R.P.M. … … … … … … 6,700-9,000 rpm
Fuel/Oil Mixture Ratio. … … … … … … … … … 32:1