Stihl MS 661 C-M

75MS 661, MS 661 C-M
8.7.6 Cut-off engine speed is not reached
– Check air filter and spark arresting
screen in muffler (if fitted)
and clean or replace if necessary,
b 13.1, b 6.1
– Check chain tension and
chain lubrication
–Calibrate the control unit,
b 8.1
Max. engine speed
above 13,000 rpm?
Maximum engine speed less
than 13,000 rpm
– Look for fault in fuel
system, check
engine for leaks,
b 13.11, b 13.5,
b 6.2
no
Troubleshooting
completed
yes
– Check plug connections on
control unit,
b 8.3.6, b 8.3.3
Connection
and tightness of
connector in
order?
– Check connectors,
replace insulated housing
or wiring harnessif
necessary, b 7.10
no
yes
– Check start detection,
wires, plug and screw
connections, b 8.3.5,
b 8.3.3
– Replace switch unit,
b 8.5
yes
no
Specified values
obtained?, b 8.3.6