Stihl MS 661 Manual page 60

2 3
Check operation
of switch shaft:
– Short circuit wire chafed?
– Function between contact spring and switch
shaft contact:
– Position " F " = no connection
0
– Position " " = connection
– replace the wiring harness if necessary,
b 7.9
Ignition spark?
yes
no
Replace control unit,
b 7.2
Engine
yes no
runs?
Machine runs trouble-free, – Look for fault in fuel system or
no further action necessary carburetor.
– Check engine for leaks.
– Check position of flywheel on
crankshaft,
b 3.6, b 6.2
MS 661, MS 661 C-M 59