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5

MS 780, MS 880

2.

Safety Precautions

If the power tool is started up in the 
course of repairs or maintenance 
work, observe all local and country-
specific safety regulations as well 
as the safety precautions and 
warnings in the instruction manual.

Gasoline is an extremely flammable 
fuel and can be explosive in certain 
conditions.

Always wear suitable protective 
gloves for operations in which 
components are heated for 
assembly or disassembly.

Improper handling may result in 
burns or other serious injuries.

Do not smoke or bring any fire, 
flame or other source of heat near 
the fuel. All work with fuel must be 
performed outdoors only. Spilled 
fuel must be wiped away 
immediately.

Always perform leakage test after 
working on the fuel system and the 
engine.

Fuel system – hose barb 
connectors

Pull off or push on fuel hoses in line 
with the connector, preferably by 
hand, to ensure the tightness of the 
fuel system.

Avoid damaging the hose barb 
– do not use sharp-edged pliers, 
screwdrivers, etc.

Do not cut open fuel hoses with a 
knife or similar tool.

Do not re-use fuel hoses after 
removal. Always install new hoses 
– fuel hoses may be overstretched 
during removal.

Install new fuel hoses either dry or 
with the aid of STIHL press fluid, 

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16

Other press fluids are not approved 
and may result in damage to the fuel 
hoses.

Coat the ends of the hoses and the 
connectors with STIHL press fluid 
and then push the new hoses on to 
the hose barbs, 

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16.

Summary of Contents for MS 880

Page 1: ...STIH STIHL MS 780 880 2009 08...

Page 2: ...ion Timing 54 9 2 Ignition Module 54 9 2 1 Removing and Installing Version with two mounting screws 54 9 2 2 Removing and Installing Version with three mounting screws 56 9 3 Testing the Ignition Modu...

Page 3: ...the Carburetor Walbro Carburetor 105 14 6 1 Metering Diaphragm 105 14 6 2 Inlet Needle 106 14 6 3 Fixed Jet 107 14 6 4 Pump Diaphragm 107 14 6 5 Choke Shaft Choke Shutter 108 14 6 6 Throttle Shaft Th...

Page 4: ...bers to identify the tools in the STIHL Special Tools manual The manual lists all special servicing tools currently available from STIHL Symbols are included in the text and pictures for greater clari...

Page 5: ...re carrying out repairs or mounting the machine to the assembly stand Always use original STIHL replacement parts They can be identified by the STIHL part number the logo and the STIHL parts symbol K...

Page 6: ...rmed outdoors only Spilled fuel must be wiped away immediately Always perform leakage test after working on the fuel system and the engine Fuel system hose barb connectors Pull off or push on fuel hos...

Page 7: ...0 5 bar under vacuum 0 5 bar 0 5 bar 3 2 Fuel System Carburetor leakage test at gauge pressure 0 8 bar Operation of tank vent at gauge pressure 0 5 bar Fuel as in instruction manual 3 3 Ignition Syst...

Page 8: ...Cover spur gear crankcase 3 0 4 M 10x1 Decompression valve 14 0 Nut M 5 Filter cover twist lock 1 0 Nut M 5 Flange carburetor tank housing 5 0 Screw P 6x32 5 Handlebar right stiffener tank housing 8...

Page 9: ...0 Spark plug M 14x1 25 Spark plug 25 0 Screw M 5x25 Ignition module crankcase old MS 880 9 0 1 4 Screw M 5x20 Ignition module crankcase 8 0 5 Screw M 6x30 Cylinder crankcase 15 0 4 Remarks 1 Loctite...

Page 10: ...le speed too high Check carburetor settings and readjust properly if necessary Clutch springs stretched or fatigued Replace the clutch springs or install new clutch Clutch spring hooks broken Replace...

Page 11: ...n sprocket worn Fit new chain sprocket Saw chain stops under load at full throttle Clutch shoes badly worn Install new clutch Clutch drum badly worn Install new clutch drum Brake band does not release...

Page 12: ...p body Valve in oil tank blocked Clean or replace valve Spur gear broken Fit new spur gears Oil pump damaged or worn Install new oil pump Machine losing chain oil Oil pump body damaged Install new oil...

Page 13: ...almost without resistance crankshaft does not turn Guide pegs on pawls or pawls themselves are worn Fit new pawls Spring clip on pawl fatigued Fit new spring clip Spring clip installed wrong Install s...

Page 14: ...ixture too much oil Use correct mixture of fuel and oil Incorrect air gap between ignition module and flywheel Set air gap correctly Flywheel cracked or damaged or pole shoes have turned blue Install...

Page 15: ...Install new spark plug Faulty insulation or short in short circuit wire Check short circuit wire for short circuit to ground Break in ignition lead or insulation damaged Check ignition lead and repla...

Page 16: ...Fit a new metering diaphragm Metered diaphragm deformed Fit a new metering diaphragm Poor acceleration Air filter dirty Clean air filter or replace if necessary Setting of low speed screw too lean Che...

Page 17: ...ed Clean the carburetor Low speed screw too rich or too lean Reset low speed screw L correctly Setting of idle speed screw LA incorrect throttle shutter completely closed Reset idle speed screw LA cor...

Page 18: ...in carburetor replace if necessary Leak on fuel hose from tank to carburetor Seal connections or install new fuel hose Setting of high speed screw H too rich Check basic carburetor setting correct if...

Page 19: ...ver full power or runs erratically Piston rings worn or broken Fit new piston rings Muffler spark arresting screen carbonized Clean the muffler inlet and exhaust replace spark arresting screen replace...

Page 20: ...ip arrow Pull off the roller 1 1 2 3 165RA002 TG 1 216RA001 TG Hold the guide lug 1 steady and unscrew the nut 2 Unscrew the nuts arrows Remove the spiked bumper 3 Always use new self locking nuts Rea...

Page 21: ...BUY NOW Then Instant Download the Complete Manual Thank you very much...

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