Bolens TB144 Trimmer User Manual


 
15
MAINTENANCE AND REPAIR INSTRUCTIONS
3. Disconnect the spark plug wire.
4. Clean dirt from around the spark plug. Remove the
spark plug from the cylinder head by turning it
counterclockwise with a 5/8” socket.
5. Remove the engine cover.
NOTE: To ease engine cover removal, pull the starter
rope out a little to give some slack.
6. 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. 27). Remove the rocker arm cover and gasket.
Rocker Arm Cover
Fig. 27
Spark Plug Hole
Gasket
Remove
Screws
Engine Cover
Fig. 25
Muffler
ROCKER ARM CLEARANCE
The rocker arm clearance may need adjustment if your
unit suffers a loss of performance power or has trouble
starting. Adjusting the rocker arm clearance requires
disassembly of the engine. If you feel unsure or
unqualified to perform this, take the unit to a Sears or
other qualified service dealer.
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.
To adjust the rocker arm clearance:
1. Remove the two (2) screws on top of the engine cover
with a Flat-head or T-25 Torx screwdriver (Fig. 25).
2. Remove the screw behind the engine cover (Fig. 26).
Top View Of The Engine
Screw
Fig. 26
1
23
Idle Adjustment Screw
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 a Troy-Bilt or other
qualified service dealer.
Fig. 22
NOTE: Ensure the tines are not in contact with the
ground when adjusting the idle.
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. 22). Turn the idle speed screw in, clockwise, 1/8 of
a turn at a time (as needed) until the engine idles
smoothly.
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.