Engine; Muffler - Stihl MS 661 Manual

6.

Engine

6.1

Muffler

Always check and, if necessary,
repair the fuel system, carburetor,
air filter and ignition system before
looking for faults on the engine.
– Check M-Tronic models with
STIHL MDG 1 using
troubleshooting chart, b 8.7
– Troubleshooting, b 3
To ensure that no dirt particles enter
the cylinder, set the piston to top
dead center before removing the
muffler – top dead center is reached
when the magnet poles ("N / S") on
the flywheel face upwards.
1
2
: Take out the screws (1, 2).
: Remove the top casing (3),
check it and replace if necessary.
2 2
: Remove the gasket (1) and take
out the screws (2)
– always install a new gasket.
24
– Remove and inspect the muffler
and replace it if necessary.
: Remove oil muffler gasket (1)
and heat shield (2) – always
install a new gasket.
– Remove and install the spark
arresting screen – see instruction
manual.
1
Installing
3
2
– Clean away any dirt from the
cylinder and exhaust port.
: Check and clean the sealing
faces (arrows) on exhaust port,
1
heat shield and muffler, remove
any gasket residue – make sure
there is no gasket residue or dirt
particles in the exhaust port.
Always replace components with
damaged sealing faces.
2
: Insert screws (1) through the
1
: Hold the heat shield (3) with the
: Coat screw holes (arrows) and
: Carefully place muffler (1) with
– Check position of muffler gasket
: Insert and tighten down the
2
3
muffler and fit the muffler
gasket (2).
pegs facing the muffler so that
the contour (arrow) is next to the
muffler outlet and then push it
into position.
2
1
screws (2) with threadlocking
adhesive
– only coat threads in screw
holes (arrows), not the pilot
holes, b 16
gasket and heat shield in position
and insert the screws (2).
and heat shield.
screws (2) firmly.
MS 661, MS 661 C-M
1
1
2