Service Manual
remove the muffler from the engine by removing
the loose carbon from the muffler using com-
the two retaining nuts and the through bolt (Figure
pressed air. Install the muffler using a new gasket
2-3).
and attach it with proper fasteners tightened to
the correct torque. See page
1-5.
DECARBONING CYLINDER HEAD
If the exhaust ports and muffler show signs of ex-
cessive carbon buildup,
it
may be necessary to
de-carbon the cylinder head. To accomplish this the
entire engine must be disassembled to allow
access into the combustion chamber. (See Dis-
assembly Instructions Page IV-1.) Remove the
carbon deposits from the piston and the cylinder
chamber using a wooden stick. TAKE CARE NOT
TO SCRATCH THE PISTON
OR
CYLINDER
CHAMBER AND DO NOT USE A METAL TOOL TO
REMOVE THE DEPOSITS.
Figure 2-3
Check the cylinder exhaust port.
If
necessary,
remove the carbon deposits from the port using
a wooden stick. Also clean the small hole next to
the exhaust port. This hole acts as a compression
relief to lessen the force required to start the
engine.
If
plugged, the recoil starter will be hard
to pull (Figure 2-4).
POSITS, ROTATE THE CRANKSHAFT TO
CLOSE THE EXHAUST PORT WITH THE PIS-
TON. THIS WILL PREVENT LOOSE CARBON
DEPOSITS FROM FALLING INTO THE CYLIN-
DER. TAKE CARE NOT TO SCRATCH THE
PISTON AND DO NOT USE
A
METAL TOOL TO
REMOVE THE DEPOSITS.
IMPORTANT: WHEN REMOVING CARBON DE-
\
Before installing the muffler check for cracks and
leaks. Inspect the inlet and outlet for carbon
buildup. Remove excessive deposits with a
scraping tool and soak the muffler in solvent to
remove wet oil deposits. Allow to air dry or dry
with compressed air. Remove the muffler heat
shield and tap the muffler body with a plastic
hammer
to
loosen the carbon deposits. Blow all
11-2
IGNITION
TIMING
(MODEL
47P22
ONLY)
To check the timing
it
is necessary to remove the
air cleaner to view the flywheel. (See Disassembly
Instructions.) The flywheel has a group of three
raised marks on its outer edge. The center mark
corresponds to BTDC and the others represent
the tolerance of plus or minus 2O.Connect one lead
of the timing tester to the engine frame (ground).
(A
timing tester must be used. An Ohmmeter or conti-
nuity light will not indicate the position of the con-
tact points.) Disconnect the wire at the ignition
switch under the fuel tank and connect the other
tester lead to this wire (Figure2-5).Turn theengine
crankshaft in its normal rotation, counter-clockwise
as viewed from the output end. The contact points
should open, as indicated by the timing tester, when
the pointer on thecrankcase housing points to the
Center of the
three
marks on the flywheelcasting.
If
the timing is wrong the flywheel must be removed
and the contact points re-gapped or replaced.
Models 47PD3, 47PE4 and 47PF5 use solid state
ignition systems and have their timing fixed at
BTDC.
Figure 2-4
Figure
2-5