3"
ENGINE
3
..
1 Construction
Series 028 chain saws are powered
by an
air-cooled, single cylinder
two-stroke
engine
..
The crankcase is a
two-part
pres-
sure die-casting made of a
special
magnesium alloy.. The
two-part
drop-forged crankshaft is supported
in two
deep-groove
ball bearings
..
Two oil seals, in the crankcase
atthe
ignition side and in the ball bearing
3.2
Troubleshooting Chart
Fault
Engine does not start easily,
stalls
at idle speed, but operates
normally at full throttle
Engine
does
not
deliver
full power
or
runs erratically
Engine overheating
at the other side,
hermetically seal
the crank chamber.
The connecting rod,
also
drop-for-
ged, is supported on needle cages
both on the crankpin and the piston
pin.
Once the needle cage and the
connecting rod have been fitted, the
two
halves of the crankshaft are
pressed together to form a torsio-
nally rigid assembly and then
First check
fuel supply, carburetor,
air
filter and ignition system before
looking for faults on the engine
..
Cause
Oil seals in crankcase
leaking
Elbow
connector leaking
Crankcase damaged (cracks)
Secondary
air
seepage into engine
through
poorly mounted
or
faulty elbow connector
Piston rings leaking
or
broken
Insufficient cylinder cooling
..
Air inlet opening in fan housing
blocked
or
cooling fins
on
cylinder plugged
15
machine finished
..
For this reason a
replacement crankshaft can only
be
supplied
complete with connec-
ting rod and needle sleeve.
Cylinder and piston are made of a
special aluminum alloy" The cylin-
der bore is impregnated in a special
process
..
Remedy
Replace oil seals
Seal
or
replace elbow connector
Replace crankshaft
Mount
elbow connector correctly
or
replace
Replace
piston rings
Thoroughly clean all cooling
air
openings
To Next Page
Loading...
