Stihl FS 50 User Manual

1Series 4144 Powerhead
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© ANDREAS STIHL AG & Co. KG, 2008
RA_938_01_01_01
1. Introduction 2
2. Safety Precautions 3
3. Specifications 4
3.1 Engine 4
3.2 Ignition System 4
3.3 Tightening
Torquese 5
4. Troubleshooting 6
4.1 Clutch 6
4.2 Ignition System 7
4.3 Engine 9
5. Clutch 10
5.1 Clutch Drum 10
5.2 Clutch 11
6. Engine 13
6.1 Leakage Test 13
6.1.1 Preparations 13
6.1.2 Vacuum Test 14
6.1.3 Pressure Test 15
6.2 Oil seals 15
6.3 Removing and
Installing
the Engine 17
6.4 Removing and
Installing
the Cylinder 17
6.5 Crankshaft 21
6.5.1 Removing and
Installing 21
6.6 Bearings /
Crankshaft 23
6.7 Piston 24
6.7.1 Piston Ring 27
7. Ignition System 27
7.1 Ignition Module 28
7.1.1 Removing and
Installing 28
7.2 Ignition Timing 29
7.3 Testing
the Ignition Module 30
7.4 Spark Plug Boot 31
7.5 Flywheel 32
7.6 Ignition System
Troubleshooting 33
8. Special Servicing
Tools 36
9. Servicing Aids 38
Contents

Stihl FS 50 Specifications

General

Engine Displacement	27.2 cc
Power Output	0.8 kW
Engine Type	2-stroke
Shaft Type	Straight
Starter System	Recoil
Overall Length	147 cm
Vibration Level	4.5 m/s²