Troy-Bilt PONY TB465SS - Manual (Page 11)

11
MAINTENANCE AND REPAIR INSTRUCTIONS
CARBURETOR ADJUSTMENT
The idle speed of the engine is
adjustable. An idle adjustment
screw is reached though a hole
in the top of the engine cover
(Fig. 34).
NOTE: Careless adjustments
can seriously damage
your unit. An authorized
service dealer should
make carburetor
adjustments.
Check Fuel
Old fuel is usually the reason for
improper unit performance.
Drain and refill the tank with fresh fuel prior to making any
adjustments. Refer to Oil and Fuel Information.
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. This is often mistaken
for an out of adjustment carburetor. Check the condition of the
air filter before adjusting the idle speed screw. Refer to Air
Filter Maintenance.
Adjust Idle Speed Screw
If, after checking the fuel 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 at a high idle for a minute to
warm up. Refer to Starting/Stopping Instructions.
2. Release the throttle trigger and let the engine idle. If the
engine stops, insert a small phillips or flat blade screwdriver
into the hole in the air filter/muffler cover (Fig. 34). Turn the
idle speed screw in, clockwise, 1/8 of a turn at a time (as
needed) until the engine idles smoothly.
Checking the fuel, cleaning the air filter, and adjusting the idle
speed should solve most engine problems. If not and all of the
following are true:
• 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.
ROCKER ARM CLEARANCE
This requires disassembly of the engine. If you feel unsure or
unqualified to perform this, take the unit to an authorized
service center.
NOTE: Inspect the valve to rocker arm clearance with a feeler
gauge after the first 10 hours of operation and then
every 25 hours of operation thereafter.
• The engine must be cold when checking or adjusting the
valve clearance.
• This task should be performed inside, in a clean, dust free
area.
1. Remove the muffler cover by pressing down on it,
separating it from the engine cover. Using a flat blade
screwdriver, disengage the middle and front tabs and slots
first. The cover will hinge off from the rear tab (Fig. 35).
2. Remove the two (2) screws on top of the engine cover with a
Flat-head or T-25 Torx screwdriver (Fig. 36).
3. Remove the screw behind the engine cover (Fig. 37).
4. Disconnect the spark plug wire.
5. Clean dirt from around the spark plug. Remove the spark
plug from the cylinder head by turning a 5/8 in. socket
counterclockwise.
6. Remove the engine cover (Fig. 36).
Idle Adjustment Screw
Fig. 34
7. Clean dirt from around the rocker arm cover. Remove the
screw holding the rocker arm cover with a large flat blade
screwdriver or Torx T-25 bit (Fig. 38). Remove the rocker
arm cover and gasket.
8. Pull the starter rope slowly to bring the piston to the top of its
travel, (known as top dead center). Check that:
• The piston is at the top of its
travel while looking in the
spark plug hole (Fig. 38)
• Both rocker arms move freely,
and both valves are closed
If these statements are not true,
repeat this step.
9. Slide the feeler gauge between
the rocker arm and the valve
return spring. Measure the clear-
ance between the valve stem and
rocker arm (Fig. 39). Measure both
the intake and exhaust valves.
The recommended clearance for
the intake and exhaust is .003 –
.006 in. (.076 – 0.152 mm). Use a
standard automotive feeler gauge at
.005 (0.127mm). The feeler gauge
should slide between the rocker arm
and valve stem with a slight amount
of resistance, without binding. Figure
40 shows how to measure the
clearance.
Fig. 35
Engine Cover
Front Slot
Front Tab
Middle Tab
Middle Slot
Rear Slot
and Tab
Remove Screws
Engine Cover
Fig. 36
Muffler
Top View Of The Engine
Screw
Fig. 37
Rocker
Arm
Cover
Fig. 38
Spark
Plug
Hole
WARNING: To prevent serious personal injury, make
sure the cutting attachment has stopped rotating before
you turn it off and set it down.
WARNING: The cutting attachment may spin during idle
speed adjustments. Wear protective clothing and observe all
safety instructions to prevent serious personal injury.