Stihl MS 650

100 MS 650, MS 660
System in order
Pull connectors off
heater switch
Test front handle
heating element
Resistance about. 7 Ω?
Check heater switch
(contact sleeve against switch housing)
Closed: about 0 Ω ?
Open: Circuit interrupted
(On machines with carburetor heating,
refit connector pin of wire
from heating element in the
round plug)
no
no
Install new
front handle
Install new
heater switch
yes
yes
Test ground wire between connector tags
and crankcase
Resistance between connectors tags and
crankcase about 0 Ω ?
no
Install new
ground wire
yes
1
2
3