Troubleshooting Chart - Stihl MS 650 Manual

13.2

Troubleshooting Chart

Measure resistance of
heating element at
temperature = +20°C (68°F)
Resistance
approx. 8 Ohm?
Check thermostatic
switch
Does thermostatic switch
close between + 13°C (55°F) and
+ 6°C (43°F)?
Does thermostatic switch
open between + 6°C (43°F) and
above + 13°C (55°F)?
Carburetor heating system
in order
MS 650, MS 660
yes
yes
yes
Replace heating
no
element
Replace thermostatic
no
switch
Replace thermostatic
no
switch
93