Product Instruction Manual
Page 3
...the risk of its products. STIHL's philosophy is important that you read and 53 understand and follow the maintenance and safety precautions in Muffler 38 Spark Plug 39 Replacing the Starter Rope ...and Rewind Spring 40 Storing the Machine 42 Checking and Replacing the Chain Sprocket 43 Maintaining and Sharpening the Saw Chain 44 Maintenance and Care 47 { Main Parts Specifications Special Accessories Ordering Spare Parts Maintenance and Repairs STIHL Incorporated Federal Emission Control Warranty Statement Trademarks MS 311, MS...
...the risk of its products. STIHL's philosophy is important that you read and 53 understand and follow the maintenance and safety precautions in Muffler 38 Spark Plug 39 Replacing the Starter Rope ...and Rewind Spring 40 Storing the Machine 42 Checking and Replacing the Chain Sprocket 43 Maintaining and Sharpening the Saw Chain 44 Maintenance and Care 47 { Main Parts Specifications Special Accessories Ordering Spare Parts Maintenance and Repairs STIHL Incorporated Federal Emission Control Warranty Statement Trademarks MS 311, MS...
Product Instruction Manual
Page 8
...saw chain saw with the cap and the detent on the spark plug - In order to loosen or come off ). Before Starting Take off the engine and then tighten. Never operate your manual. Proper tension of injury. 6 MS 311, MS 391 Proper starting , particularly the throttle trigger, throttle trigger ... match each other similar tool can cause an improperly tightened fuel filler cap to reduce the risk of the instruction manual.) Warning! STIHL Oilomatic chain, guide bar and sprocket must move freely and always spring back to maintain a firm grip and properly control your instruction...
...saw chain saw with the cap and the detent on the spark plug - In order to loosen or come off ). Before Starting Take off the engine and then tighten. Never operate your manual. Proper tension of injury. 6 MS 311, MS 391 Proper starting , particularly the throttle trigger, throttle trigger ... match each other similar tool can cause an improperly tightened fuel filler cap to reduce the risk of the instruction manual.) Warning! STIHL Oilomatic chain, guide bar and sprocket must move freely and always spring back to maintain a firm grip and properly control your instruction...
Product Instruction Manual
Page 12
...It can cause severe or fatal injury, respiratory illness or cancer. Warning! You may be cutting asbestos, immediately contact your STIHL servicing dealer only. 10 MS 311, MS 391 Warning! Warning! The muffler and other parts while they may occur if the throttle is depressed for a short period ...injury in the cut or the chain brake is equipped with a damaged or missing chain catcher. In the event of the cylinder, spark plug) become hot during normal operation may be flung off the engine immediately - Always stop switch to time, the catcher may also ...
...It can cause severe or fatal injury, respiratory illness or cancer. Warning! You may be cutting asbestos, immediately contact your STIHL servicing dealer only. 10 MS 311, MS 391 Warning! Warning! The muffler and other parts while they may occur if the throttle is depressed for a short period ...injury in the cut or the chain brake is equipped with a damaged or missing chain catcher. In the event of the cylinder, spark plug) become hot during normal operation may be flung off the engine immediately - Always stop switch to time, the catcher may also ...
Product Instruction Manual
Page 24
... snugly onto spark plug terminal of the band on the wood. The amount of the chain brake and can spot a dull chain when easy-to-cut wood becomes hard to reduce the risk of fire and hearing loss. For these reasons, each STIHL chain saw in the boot may reduce ...friction of the proper size. (Note: If terminal has detachable SAE adapter nut, it is damaged, missing or modified. The chain saw is a change in the instruction manual). 22 MS 311, MS 391 English Warning! Warning! twice a year...
... snugly onto spark plug terminal of the band on the wood. The amount of the chain brake and can spot a dull chain when easy-to-cut wood becomes hard to reduce the risk of fire and hearing loss. For these reasons, each STIHL chain saw in the boot may reduce ...friction of the proper size. (Note: If terminal has detachable SAE adapter nut, it is damaged, missing or modified. The chain saw is a change in the instruction manual). 22 MS 311, MS 391 English Warning! Warning! twice a year...
Product Instruction Manual
Page 35
... - Open the throttle only when the chain brake is off engine N Press the button on (saw is cold MS 311, MS 391 33 see "Spark plug" N Dry spark plug N Crank the engine several times with the throttle slightly open N if necessary, configure for use. Increased engine speeds.... even if the engine is ready for winter operation, see "Spark plug" N Set the Master Control lever to the stop position 0 N Remove the spark plug - N Move the Master Control lever to clear the combustion chamber N Replace the spark plug - Once the engine is released - the Master Control lever ...
... - Open the throttle only when the chain brake is off engine N Press the button on (saw is cold MS 311, MS 391 33 see "Spark plug" N Dry spark plug N Crank the engine several times with the throttle slightly open N if necessary, configure for use. Increased engine speeds.... even if the engine is ready for winter operation, see "Spark plug" N Set the Master Control lever to the stop position 0 N Remove the spark plug - N Move the Master Control lever to clear the combustion chamber N Replace the spark plug - Once the engine is released - the Master Control lever ...
Product Instruction Manual
Page 41
... to start or runs poorly at part throttle etc.) affect the condition of spark plug: N Too much oil in fuel mix. N Pull off the spark plug boot N Unscrew spark plug Remove the spark plug N Move the Master Control lever to form on the insulator nose which may... first check the spark plug. operating at idling speed, first check the spark plug. If engine is blocked 1 4903BA007 KN English N Remove spark plug - Wrong fuel mix (too much engine oil in operation. N Use only resistor type spark plugs of the spark plug. MS 311, MS 391 39 Fit a new spark plug after approx. 100...
... to start or runs poorly at part throttle etc.) affect the condition of spark plug: N Too much oil in fuel mix. N Pull off the spark plug boot N Unscrew spark plug Remove the spark plug N Move the Master Control lever to form on the insulator nose which may... first check the spark plug. operating at idling speed, first check the spark plug. If engine is blocked 1 4903BA007 KN English N Remove spark plug - Wrong fuel mix (too much engine oil in operation. N Use only resistor type spark plugs of the spark plug. MS 311, MS 391 39 Fit a new spark plug after approx. 100...
Product Instruction Manual
Page 42
... crankcase and remove downwards 4903BA005 KN 40 MS 311, MS 391 the saw chain is blocked 1 2 1 1 N Loosen screws (1) N Remove the shroud (2) Removing the fan housing 1 1 1 1 N Remove screws (1) N Push hand guard upward N Pull the bottom of fire and burn injury, use only spark plugs authorized by STIHL. 4903BA002 KN English Install spark plug 1 N Screw in the boot may create...
... crankcase and remove downwards 4903BA005 KN 40 MS 311, MS 391 the saw chain is blocked 1 2 1 1 N Loosen screws (1) N Remove the shroud (2) Removing the fan housing 1 1 1 1 N Remove screws (1) N Push hand guard upward N Pull the bottom of fire and burn injury, use only spark plugs authorized by STIHL. 4903BA002 KN English Install spark plug 1 N Screw in the boot may create...
Product Instruction Manual
Page 50
...and preheating port Clean (winter operation only) Carburetor Check idle adjustment - chain must not rotate X X Readjust idle Spark Plug Readjust electrode gap Replace after every 100 operating hours All accessible screws and nuts (not adjusting screws) 3) Retighten Sparl ... Chain catcher Replace Safety labels Replace 1) STIHL recommends a STIHL servicing dealer. 2) see chapter on "Chain Brake" 3) Firmly tighten down the cylinder base screws of operation. 4) not in all versions, market-specific X X X X X X X X X X 48 MS 311, MS 391 before starting work after finishing work ...
...and preheating port Clean (winter operation only) Carburetor Check idle adjustment - chain must not rotate X X Readjust idle Spark Plug Readjust electrode gap Replace after every 100 operating hours All accessible screws and nuts (not adjusting screws) 3) Retighten Sparl ... Chain catcher Replace Safety labels Replace 1) STIHL recommends a STIHL servicing dealer. 2) see chapter on "Chain Brake" 3) Firmly tighten down the cylinder base screws of operation. 4) not in all versions, market-specific X X X X X X X X X X 48 MS 311, MS 391 before starting work after finishing work ...
Product Instruction Manual
Page 51
... 2 4 # 1 6 11 7 12 8 10 9 13 16 17 15 18 20 22 19 23 21 14 24 English 1 Shroud Lock 2 Carburetor Adjusting Screws 3 Spark Plug Boot 4 Shutter (Summer and Winter Operation) 5 Decompression Valve (Automatically Resetting) 6 Chain Brake 7 Chain Sprocket 8 Chain Sprocket Cover 9 Chain Catcher 10 Side Chain Tensioner 11... Bumper Spike 12 Guide Bar 13 Oilomatic Saw Chain 14 Oil Filler Cap 15 Muffler (with Spark Arresting Screen, not Fitted on all Markets) 16 Front Hand Guard 17 Front Handle (Handlebar) 18 Starter Grip 19 Fuel Filler Cap ...
... 2 4 # 1 6 11 7 12 8 10 9 13 16 17 15 18 20 22 19 23 21 14 24 English 1 Shroud Lock 2 Carburetor Adjusting Screws 3 Spark Plug Boot 4 Shutter (Summer and Winter Operation) 5 Decompression Valve (Automatically Resetting) 6 Chain Brake 7 Chain Sprocket 8 Chain Sprocket Cover 9 Chain Catcher 10 Side Chain Tensioner 11... Bumper Spike 12 Guide Bar 13 Oilomatic Saw Chain 14 Oil Filler Cap 15 Muffler (with Spark Arresting Screen, not Fitted on all Markets) 16 Front Hand Guard 17 Front Handle (Handlebar) 18 Starter Grip 19 Fuel Filler Cap ...
Product Instruction Manual
Page 52
...Grip The grip of the pull starter, for starting throttle, run and stop the rotation of the chain. Spark arresting screen is accelerated beyond idle speed. (not illustrated) Anti-Vibration System The anti-vibration system includes ...Front Handle (Handlebar) Handlebar for the shroud. 2 Carburetor Adjusting Screws For tuning the carburetor. 3 Spark Plug Boot Connects the spark plug with Spark Arresting Screen, not Fitted on all Markets) Muffler reduces engine exhaust noise and diverts exhaust gases away... and cutting attachment to the operator's hands. (not illustrated) 50 MS 311, MS 391
...Grip The grip of the pull starter, for starting throttle, run and stop the rotation of the chain. Spark arresting screen is accelerated beyond idle speed. (not illustrated) Anti-Vibration System The anti-vibration system includes ...Front Handle (Handlebar) Handlebar for the shroud. 2 Carburetor Adjusting Screws For tuning the carburetor. 3 Spark Plug Boot Connects the spark plug with Spark Arresting Screen, not Fitted on all Markets) Muffler reduces engine exhaust noise and diverts exhaust gases away... and cutting attachment to the operator's hands. (not illustrated) 50 MS 311, MS 391
Product Instruction Manual
Page 53
...hp (3.1 kW) at 9500 rpm Idle speed: 2800 rpm Maximum permissible speed with bar and chain: 13000 rpm Ignition system Electronic magneto ignition Spark plug (suppressed): Electrode gap: NGK BPMR 7 A, Bosch WSR 6 F 0.02 in. (0.5 mm) Fuel system All position diaphragm carburetor with ...11.8 oz (0.350 l) Weight English dry, without bar and chain MS 311: 14.1 lbs. (6.4 kg) MS 391: 14.1 lbs. (6.4 kg) Cutting attachment Recommended cutting attachments in . (1.6 mm) Sprocket nose: 10- Rollomatic E guide bars STIHL reduced kickback guide bars (with green label) Bar lengths: 16, ...
...hp (3.1 kW) at 9500 rpm Idle speed: 2800 rpm Maximum permissible speed with bar and chain: 13000 rpm Ignition system Electronic magneto ignition Spark plug (suppressed): Electrode gap: NGK BPMR 7 A, Bosch WSR 6 F 0.02 in. (0.5 mm) Fuel system All position diaphragm carburetor with ...11.8 oz (0.350 l) Weight English dry, without bar and chain MS 311: 14.1 lbs. (6.4 kg) MS 391: 14.1 lbs. (6.4 kg) Cutting attachment Recommended cutting attachments in . (1.6 mm) Sprocket nose: 10- Rollomatic E guide bars STIHL reduced kickback guide bars (with green label) Bar lengths: 16, ...
Product Instruction Manual
Page 57
...Start Enrichment System) - Spark Plug - and #3,400,476) 4-MIX® AUTOCUT® EASYSTART® FARM BOSS® OILOMATIC® STIHL Cutquik® STIHL DUROMATIC® STIHL Quickstop® STIHL ROLLOMATIC® STIHL WOOD BOSS® TIMBERSPORTS® YARD BOSS® Some of STIHL's Common Law Trademarks The...in this recommendation regarding quality and mixing ratio of the recommended 2-stroke fuel-oil MS 311, MS 391 55 Clamps - damages to other engine components caused by STIHL Incorporated, and N replacement of parts and other services and adjustments necessary for ...
...Start Enrichment System) - Spark Plug - and #3,400,476) 4-MIX® AUTOCUT® EASYSTART® FARM BOSS® OILOMATIC® STIHL Cutquik® STIHL DUROMATIC® STIHL Quickstop® STIHL ROLLOMATIC® STIHL WOOD BOSS® TIMBERSPORTS® YARD BOSS® Some of STIHL's Common Law Trademarks The...in this recommendation regarding quality and mixing ratio of the recommended 2-stroke fuel-oil MS 311, MS 391 55 Clamps - damages to other engine components caused by STIHL Incorporated, and N replacement of parts and other services and adjustments necessary for ...
Parts Diagram
Page 10
... 998 0603 1 Torsion spring 5 1106 405 1000 1 Spark plug boot 6 0000 435 8400 1 Sleeve 7 0000 400 7000 1 Spark plug NGK BPMR7A 7 1110 400 7005 1 Spark plug Bosch WSR 6 F 8 9075 478 3018 2 Pan head self-tapping screw IS-D4x18 9 9291 021 0100 2 Washer 4.3 10 1140 440 3003 1 Wiring harness (1) MS 311, (2) MS 311-Z, (3) MS 391, (4) MS 391-Z MS 311, MS 391 10 SCS 01-2010 3.29
... 998 0603 1 Torsion spring 5 1106 405 1000 1 Spark plug boot 6 0000 435 8400 1 Sleeve 7 0000 400 7000 1 Spark plug NGK BPMR7A 7 1110 400 7005 1 Spark plug Bosch WSR 6 F 8 9075 478 3018 2 Pan head self-tapping screw IS-D4x18 9 9291 021 0100 2 Washer 4.3 10 1140 440 3003 1 Wiring harness (1) MS 311, (2) MS 311-Z, (3) MS 391, (4) MS 391-Z MS 311, MS 391 10 SCS 01-2010 3.29
User Manual
Page 2
... Decompression Valve 38 9.7 Handlebar 59 3. Introduction and 6. Chain Brake 8 7.1 Ignition Timing 7.2 Preseparator 7.3 Ignition Module 9 7.4 Testing the 10 Ignition Module 11 7.5 Spark Plug Boot / 12 Ignition Lead 13 7.6 Flywheel 16 7.7 Short Circuit Wire 7.7.1 Testing 7.7.2 Removing and 17 Installing 7.7.3 Ground Wire 19 7.7.4 Contact Spring 7.8 Ignition System Troubleshooting... Rope Rotor 52 8.5 Starter Rope / Grip 53 8.6 Tensioning the Rewind Spring 54 8.7 Replacing the Rewind Spring 55 RA_542_00_01_01 MS 311, MS 391 q © ANDREAS STIHL AG & Co.
... Decompression Valve 38 9.7 Handlebar 59 3. Introduction and 6. Chain Brake 8 7.1 Ignition Timing 7.2 Preseparator 7.3 Ignition Module 9 7.4 Testing the 10 Ignition Module 11 7.5 Spark Plug Boot / 12 Ignition Lead 13 7.6 Flywheel 16 7.7 Short Circuit Wire 7.7.1 Testing 7.7.2 Removing and 17 Installing 7.7.3 Ground Wire 19 7.7.4 Contact Spring 7.8 Ignition System Troubleshooting... Rope Rotor 52 8.5 Starter Rope / Grip 53 8.6 Tensioning the Rewind Spring 54 8.7 Replacing the Rewind Spring 55 RA_542_00_01_01 MS 311, MS 391 q © ANDREAS STIHL AG & Co.
User Manual
Page 6
... Idle speed: Clutch: Clutch engages at: Engine housing leakage test at gauge pressure: under vacuum: 2.2 Fuel System 2.3 Ignition System 2.4 Chain Lubrication MS 311, MS 391 MS 311 59 cm3 47 mm 34 mm 3 kW (4 bhp) at 9,500 rpm 13,000 rpm 2,800 rpm Centrifugal clutch without linings 3,500 rpm 0.5... Operation of tank vent at gauge pressure: Fuel: 0.8 bar 0.5 bar as specified in instruction manual Air gap between ignition module and fanwheel: Spark plug (resistor type): Electrode gap: 0.20...0.30 mm NGK BPMR 7 A BOSCH WSR6F 0.5 mm Speed-controlled oil pump with reciprocating piston and manual...
... Idle speed: Clutch: Clutch engages at: Engine housing leakage test at gauge pressure: under vacuum: 2.2 Fuel System 2.3 Ignition System 2.4 Chain Lubrication MS 311, MS 391 MS 311 59 cm3 47 mm 34 mm 3 kW (4 bhp) at 9,500 rpm 13,000 rpm 2,800 rpm Centrifugal clutch without linings 3,500 rpm 0.5... Operation of tank vent at gauge pressure: Fuel: 0.8 bar 0.5 bar as specified in instruction manual Air gap between ignition module and fanwheel: Spark plug (resistor type): Electrode gap: 0.20...0.30 mm NGK BPMR 7 A BOSCH WSR6F 0.5 mm Speed-controlled oil pump with reciprocating piston and manual...
User Manual
Page 7
...Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Carrier Screw Screw Screw Screw Screw Nut Screw Screw Spark plug Screw P 4x14 Chain tensioner cover/engine housing 1.5 P 4x12 Brake band/engine housing 2.0 M 10 Collar stud for ...collar stud 3.5 P 4x14 Pre-separator / engine housing 2.0 P 4x12 Cover plate/fan housing 2.0 M 14x1.25 Spark plug 25.0 D 4x18 Ignition module / engine pan 4.0 1) 3) 4) 3) 3) 3) 1) 3) 5) 3) 6 MS 311, MS 391 These screws form a permanent thread when they are used in polymer and light metal components. They can be removed...
...Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Screw Carrier Screw Screw Screw Screw Screw Nut Screw Screw Spark plug Screw P 4x14 Chain tensioner cover/engine housing 1.5 P 4x12 Brake band/engine housing 2.0 M 10 Collar stud for ...collar stud 3.5 P 4x14 Pre-separator / engine housing 2.0 P 4x12 Cover plate/fan housing 2.0 M 14x1.25 Spark plug 25.0 D 4x18 Ignition module / engine pan 4.0 1) 3) 4) 3) 3) 3) 1) 3) 5) 3) 6 MS 311, MS 391 These screws form a permanent thread when they are used in polymer and light metal components. They can be removed...
User Manual
Page 13
...damaged (cracks) Install new engine housing 12 MS 311, MS 391 Check operation of power Cause Remedy Spark plug boot is loose Press boot firmly onto spark plug and fit new spring if necessary Spark plug sooted, smeared with oil Clean the spark plug or replace if necessary. If sooting keeps ...oil mixture - Condition Engine runs roughly, misfires, temporary loss of spark plug. 3.5 Ignition System Exercise extreme caution while carrying out maintenance and repair work on the ignition system. Clean the spark plug or replace if necessary. too much oil Use correct mixture of ...
...damaged (cracks) Install new engine housing 12 MS 311, MS 391 Check operation of power Cause Remedy Spark plug boot is loose Press boot firmly onto spark plug and fit new spring if necessary Spark plug sooted, smeared with oil Clean the spark plug or replace if necessary. If sooting keeps ...oil mixture - Condition Engine runs roughly, misfires, temporary loss of spark plug. 3.5 Ignition System Exercise extreme caution while carrying out maintenance and repair work on the ignition system. Clean the spark plug or replace if necessary. too much oil Use correct mixture of ...
User Manual
Page 18
If the clutch is noticeably worn, replace all parts, b 14 - MS 311, MS 391 17 Clutch - Pull the clutch shoes off the spark plug. - Clean all three clutch shoes at the same time - since runout may otherwise affect correct operation of the clutch. 4903RA004 TG ... 4903RA106 TG 1 : Pull boot (1) off the carrier. : Remove the retainers (1). 1 4903RA006 TG 4903RA003 TG 1 : Push the locking strip (1) 0000 893 5903 into the spark plug hole, wide end first, so that the clutch has a left-hand thread. Note that "OBEN-TOP" faces up. 4903RA002 TG : Apply wrench to remove the...
If the clutch is noticeably worn, replace all parts, b 14 - MS 311, MS 391 17 Clutch - Pull the clutch shoes off the spark plug. - Clean all three clutch shoes at the same time - since runout may otherwise affect correct operation of the clutch. 4903RA004 TG ... 4903RA106 TG 1 : Pull boot (1) off the carrier. : Remove the retainers (1). 1 4903RA006 TG 4903RA003 TG 1 : Push the locking strip (1) 0000 893 5903 into the spark plug hole, wide end first, so that the clutch has a left-hand thread. Note that "OBEN-TOP" faces up. 4903RA002 TG : Apply wrench to remove the...
User Manual
Page 29
... upset the fuel-air mixture. 6.2.1 Preparations 1 1 1 4903RA053 TG This makes adjustment of leaks. This can be checked through the spark plug hole. - Remove the decompression valve, b 6.9 0001RA083 TG - The sealing plate must completely fill the space between the cylinder exhaust ...carburetor, b 12.5 28 MS 311, MS 391 Pull off the boot and unscrew the spark plug. - Remove the shroud, b 6.4 - Do not refit old plugs, always fit new ones. : Loosen the screws (1). 1 0001RA085 TG : Fit the plug (1) 1122 025 2200 and tighten it down firmly. : Fit the spark plug (2) and tighten it down...
... upset the fuel-air mixture. 6.2.1 Preparations 1 1 1 4903RA053 TG This makes adjustment of leaks. This can be checked through the spark plug hole. - Remove the decompression valve, b 6.9 0001RA083 TG - The sealing plate must completely fill the space between the cylinder exhaust ...carburetor, b 12.5 28 MS 311, MS 391 Pull off the boot and unscrew the spark plug. - Remove the shroud, b 6.4 - Do not refit old plugs, always fit new ones. : Loosen the screws (1). 1 0001RA085 TG : Fit the plug (1) 1122 025 2200 and tighten it down firmly. : Fit the spark plug (2) and tighten it down...
User Manual
Page 33
... screws (1). - Remove the filter base, b 12.3 - Remove the muffler, b 6.1 : Use the lug (arrow) to pry the cylinder (1) upwards. - Pull off the boot and unscrew the spark plug, - Remove the carburetor, b 12.5 - Installing - Inspect the piston and piston rings and replace if necessary, b 6.7, b 6.8 4903RA071 TG 4903RA072 TG 4903RA074 TG 32...
... screws (1). - Remove the filter base, b 12.3 - Remove the muffler, b 6.1 : Use the lug (arrow) to pry the cylinder (1) upwards. - Pull off the boot and unscrew the spark plug, - Remove the carburetor, b 12.5 - Installing - Inspect the piston and piston rings and replace if necessary, b 6.7, b 6.8 4903RA071 TG 4903RA072 TG 4903RA074 TG 32...