Stihl 4180 Series User Manual

1Series 4180 Powerhead
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© ANDREAS STIHL AG & Co. KG, 2007
Contents
1. Introduction 2
2. Safety Precautions 3
3. Specifications 4
3.1 Engine 4
3.2 Spark plug 4
3.3 Fuel System 4
3.4 Tightening Torques 5
4. Troubleshooting 7
4.1 Clutch 7
4.2 Rewind Starter 8
4.3 Ignition System 9
4.4 Carburetor 10
4.5 Engine 12
5. Rewind Starter/
Shroud 14
5.1 General 14
5.2 Removing and
Installing 14
5.3 Rope Rotor 14
5.4 Starter Rope 16
5.4.1 Tensioning 17
5.5 Pawl 18
5.6 Replacing the
Rewind Spring 18
5.7 Removing the Shroud 18
6. Fuel System 19
6.1 Air Filter 19
6.2 Carburetor 20
6.2.1 Leakage test 20
6.2.2 Removing
and Installing 21
6.2.3 Manual Fuel Pump 21
6.2.4 Metering Diaphragm 22
6.2.5 Inlet Needle 23
6.2.6 Fixed Jet 23
6.2.7 Pump Diaphragm 23
6.3 Accelerator Pump 25
6.4 Adjusting Idle Speed 25
6.4.1 Basic Setting 26
6.5 Tank Vent 27
6.5.1 Checking Operation 27
6.5.2 Replacing Tank Vent 28
6.6 Fuel Supply 29
6.6.1 Cleaning the
Fuel Tank 29
6.6.2 Fuel Hoses and
Pickup Body 29
6.6.3 Fuel Tank 31
7. Engine 31
7.1 Compression
Pressure 32
7.2 Checking / Adjusting
Valve Clearance 32
7.3 Rocker Arms/
Pushrods 34
7.4 Cam Followers,
Cam Gear 35
7.4.1 Decompression
System 36
7.5 Muffler / Spark
Arresting Screen 36
7.6 Clutch 37
7.6.1 Removing and
Disassembling 37
7.6.2 Assembling and
Installing 38
7.6.3 Clutch Drum and
Bearing 39
7.7 Flywheel 40
7.8 Crankshaft 41
7.8.1 Replacing
the Oil Seals 41
7.8.2 Crankcase,
Lower Half 43
7.8.3 Crankshaft 44
7.8.4 Piston 45
7.8.5 Piston Rings 47
7.9 Valves/Valve Springs 48
7.10 Upper Half of
Crankcase with
Cylinder 49
7.11 Leakage Test 49
8. Ignition System 51
8.1 Spark Plug Boot 51
8.2 Ignition Module 52
8.2.1 Ignition Timing 52
8.2.2 Removing and
Installing 52
8.3 Testing the Ignition
System 54
8.4 Ignition System
Troubleshooting 55
9. Throttle Control 58
9.1 Throttle Trigger,
Lockout Lever 58
9.2 Tensioner 59
9.3 Adjusting Throttle
Cable 59
9.3.1 Control Handle
with Slide 59
9.3.2 Control Handle
without Slide 60
9.3.3 Checking Adjustment 61
9.4 Slide Control 61
10. AV System 62
11. Special Servicing
Tools 63
12. Special Accessories 64

Stihl 4180 Series Specifications

General

Brand	Stihl
Model	4180 Series
Category	Engine
Language	English