Troy-Bilt TB26CO - Manual (Page 10)

10
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. 33).
2. Remove the two (2) screws on top of the engine cover with a
Flat-head or T-25 Torx screwdriver (Fig. 34).
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. 32).
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 into the hole in the air
filter/muffler cover (Fig. 32). Turn the idle speed screw in,
clockwise, 1/8 of a turn at a time (as needed) until the engine
idles smoothly.
NOTE: The cutting attachment should not rotate when the
engine idles.
3. If the cutting attachment rotates when the engine idles, turn
the idle speed screw counterclockwise 1/8 of a turn at a
time (as needed), to reduce idle speed.
MAINTENANCE AND REPAIR INSTRUCTIONS
WARNING: The cutting attachment may spin during
idle speed adjustments. Wear protective clothing and
observe all safety instructions to prevent serious
personal injury.
WARNING: To prevent serious personal injury,
make sure the cutting attachment has stopped
rotating before you turn it off and set it down.
Idle Adjustment Screw
Fig. 32
Fig. 33
Engine Cover
Front Slot
Front Tab
Middle Tab
Middle Slot
Rear Slot
and Tab
Remove
Screws Engine Cover
Fig. 34
Muffler
Top View Of The Engine
Air Filter
Air Filter
Cover
Tab
Fig. 31