Stihl BT 45 Manual

10 BT 45
Condition Cause Remedy
Poor acceleration Idle jet too lean Back off the low speed screw
slightly
(see Adjusting the Carburetor)
Main jet too lean Back off the high speed screw
slightly
(see Adjusting the Carburetor)
Inlet control lever too low
(relative to correct installed
position)
Replace the inlet control lever
Inlet needle sticking to valve seat Remove inlet needle, clean and
refit
Connecting bore to atmosphere
blocked
Clean bore
Diaphragm gasket leaking Fit new diaphragm gasket
Metering diaphragm damaged or
shrunk
Fit new metering diaphragm
Carburetor floods,
engine stalls
Inlet needle not sealing. Foreign
matter in valve seat or cone
damaged
Remove and clean or replace inlet
needle, clean fuel tank, pickup
body and fuel line if necessary
Inlet control lever sticking on
spindle
Free off inlet control lever
Helical spring not located on nipple
of inlet control lever
Remove inlet control lever and refit
correctly
Perforated disc on diaphragm is
deformed and presses constantly
against inlet control lever
Fit new metering diaphragm
Inlet control lever too low
(relative to correct installed
position)
Fit new inlet control lever

Stihl BT 45 Specifications

General

Engine Type	2-stroke
Displacement	27.2 cc
Power Output	0.9 kW (1.2 hp)
Weight	5.2 kg
Power Source	Gasoline
No-Load Speed	0 - 300 rpm