Compression - DeWalt DW168F Manual

pRoBlEM CausE
Debris is locking up flywheel
BaTTERy sTaRTER/BaTTERy FaIluRE
pRoBlEM CausE
battery does not battery leads faulty
supply electricity to
starter
battery is dead
BaTTERy sTaRTER/sTaRTER MoToR FaIluRE
pRoBlEM CausE
Starter motor fails Pinion gear not engaged with
flywheel
Solenoid faulty
Starter motor damaged
Electrical relay fails Starter toggle switch faulty

Compression

sTaRTInG pRoBlEM
pRoBlEM CausE
Poor compression Leaking/stuck valves
Head gasket burned
worn piston rings
worn cylinder bore
Warped/cracked cylinder head Replace cylinder head
pERFoRManCE pRoBlEM
soluTIon
Disassemble and clear any
debris from recoil base
and recoil assembly. See
Flywheel Ignition under
Breakdown.
soluTIon
Check for debris blocking
connections
If worn, replace battery
Charge and replace battery
pack.
soluTIon
Remove starter motor and
make sure the pinion gear
slides freely on helix
Make sure gear teeth have
not been stripped
Repair or replace starter
motor
Check for continuity on starter
toggle switch in the ON posi-
tion. See Fan Cover break-
down section.
soluTIon
Valve job/replacement
Replace head gasket
Service/replace rings or piston
or crankcase
See Compression Test.
20
pRoBlEM CausE
Engine overheats Cooling fins obstructed
Excessive load
Carbon in combustion
chamber
Low oil
Set at wrong idle speed
Low power Clogged spark arrestor
Valves leaking
Intake exhaust manifolds
clogged
Carbon build up
Black exhaust Carbon in combustion
smoke chamber
Valves leaking/stuck
Blue exhaust smoke Piston rings/cylinder bore
worn and passing oil
Can not handle load Improper valve clearance
Weak valve spring
Valve/valve seats worn or
damaged
soluTIon
Clear fins of debris
Clean combustion chamber
Clean combustion chamber
Add oil
See speed/Governor
adjustment under Perform
Test Checks.
Remove, clean and replace.
Perform valve job,
see Inspection under
Breakdowns: Cylinder Head
Valves.
Clean manifolds
Clean combustion chamber
Clean combustion chamber
Check valves/seats.
Recondition if necessary.
Check valve to valve guide
fit up.
Replace rings and piston/
hone cylinder/check air filter.
Check/adjust valve clearance
or perform valve job, see
Inspection under Cylinder
Head Valves Breakdowns.
Perform valve job, see
Inspection under Cylinder
Head Valves Breakdown.
Perform valve job, see
Inspection under Cylinder
Head Valves Breakdown.