DeWalt DW168F - Page 18

18

PROBLEM POSSIBLE CAUSE SOLUTION
Engine will
not start,
stay running
or only runs
whenchoked
(continued)
17.Vacuumleakat
carburetor
Ensure the evaporative system hose from the
charcoal canister is connected firmly to port
behind carburetor and other evaporative hoses
are connected firmly. Ensure carburetor is tightly
secured to engine by the two mounting nuts inside
air cleaner
18. No or low
compression
Refer to Compression Test under Perform Test
Checks.
19. Dirty air filter Ensureaircleaneriscleanandnotblockingairfrom
entering carburetor. Clean if necessary.
Engine will
not turn
over, engine
seized
1. Battery is dead
(Electricstart)
Tryfullychargedbattery.Replacebatterypackif
needed.
2. Recoil pull
starter rope
broken
Replace pull start rope. Refer to Recoil Starter/
Assemble Recoil Starter under Breakdowns.
3. Recoil pull start
not engaging
engine
Remove recoil assembly. Repair or replace as nec-
essary. Refer to Recoil Starter/Assemble Recoil
Starter under Breakdowns.
4. Cylinder filled
with gas.
Removesparkplugandtipenginemomentarily.If
gas pours out hole, carburetor float bowl needle is
stuckopen.Cleanorreplacecarburetor.Referto
Carburetor under Breakdowns for cleaning instruc-
tions.
NOTE: When transporting unit fuel valve must be in
OFF position, if not flooding will occur."
5. Electric starter
motor faulty
Refer to Start Mechanism under Perform Test
Checks and Starter Motor under Breakdowns for
checks.
6. Excessive
carbon buildup
in head. Engine
was possibly run
withchokein
closed or partially
closed position
instead of open.
Ensurechokemechanismoperates
correctly.
Withthechokeinthefullyopenpositionandthe
enginerunning,thechokeplateatentranceofthe
carburetor should be fully open.
Onleverchokesmovetheleverallthewaytothe
right
Replacechokemechanismifchokedoesnot
operate in this way or is damaged. Test and verify
compression is correct. Refer to Compression Test
under Perform Test Checks.
7. Internal part
failure
Withsparkplugremoved,rotateengineshaftby
handtoseeifitrotatessmoothly.Ifstilllockedup,
removecrankcasecoveranddeterminecause.
Poor
performance,
low power,
running
too fast,
Backfiring
often
1. Fuelquality
issue or
restriction
Refer to Engine will not start, stay running or
only runs when choked steps 5,6,12 & 13 under
Starting Problem/Engine under Troubleshooting.
PROBLEM POSSIBLE CAUSE SOLUTION
Poor
performance,
low power,
running
too fast,
Backfiring
often
(continued)
2. Sparkarrestor
dirty or clogged
Cleansparkarrestor,refertoSpark Arrestor under
Maintenance.Runenginebrieflywithoutspark
arrestor to verify that was the cause. Reassemble
sparkarrestortomuffler.Ifscreenisdamaged
replacesparkarrestorifscreenisdamaged.
IMPORTANT:Theseproductsareequippedwith
spark-arrestingmufflers.Itislegallyrequiredin
the state of California. It is a violation of California
statutes section 130050 and/or sec tions 4442 and
4443 of the California Public Re sourc es Code,
unlesstheengineisequippedwithasparkarrester,
as defined in section 4442, and maintained in ef fec-
tiveworkingorder.Sparkarrestersarealsorequired
on some U.S. For est Service land and may also be
legallyrequiredunderotherstatutesandordinanc-
es.
3. Worn governor
arm rivet joint
Worn carburetor
throttle actuator,
Governor arm
slipping on shaft,
  Throttlelinkages
bent
High speed
screw has been
tampered with
Ifengineisrunningover4000rpm(67Hz),first
ensurealllinkagescontrollingthethrottleposition
actuate freely without binding over full travel. NOTE:
Comparingtheoldgovernorlinkagetoanew
replacementgovernorlinkagemayhelptodeter-
mine if the components in the system are worn or
damaged.
•  The riveted joint in governor arm must pivot
freely but not be loose and sloppy.
•  Ifthehighspeedadjustingscrewhasbeentam-
pered with it can be readjusted, refer to Speed/
Governor Adjustments under Perform Test
Checks. HOWEVER, if the root cause of the high
speed is due to the governor arm slipping on the
governor shaft, adjusting the speed will give a
false indication of being correct. The speed will
beokuntilputunderaload,theenginewilldroop
or bog down. After adjusting the speed, the
unitmustbetestedusingaloadbanktesterby
gradually applying full rated load. If speed drops
more that 3 Hz, the governor arm has slipped on
the shaft and needs to be reset. To reset gover-
nor arm, refer to Speed/Governor Adjustments
under Perform Test Checks.
4. Backfiringoften
or air filter
melted, Ignition
coil could be
faulty
Replace ignition coil. NOTE: Coil resistance can
measureokandstillbefaulty.Itisbesttoreplace
coil in this case.