{ STIHL MS 661 C-M Instruction Manual
English © ANDREAS STIHL AG & Co. KG, 2018 0458-759-8321-B. VA2.H18. 0000006549_012_GB Printed on chlorine-free paper Printing inks contain vegetable oils, paper can be recycled.
English Intake air baffle: winter operation Guide to Using this Manual This Instruction Manual refers to a STIHL chain saw, also called a machine in this Instruction Manual. Intake air baffle: summer operation Pictograms Handle heating Pictograms that appear on the machine are explained in this Instruction Manual.
English Safety Precautions Special safety precautions must be observed to reduce the risk of personal injury when working with a chain saw because of the very high chain speed and very sharp cutters. It is important that you read the instruction manual before first use and keep it in a safe place for future reference. Nonobservance of the instruction manual may result in serious or even fatal injury. General Observe all applicable local safety regulations, standards and ordinances.
English Wear sturdy protective gloves made of a resistant material (e.g. leather). Clean the dust and dirt off the machine – do not use any grease solvents for this purpose. Open the fuel filler cap carefully so that any excess pressure is relieved gradually and fuel does not splash out. Clean the ventilation slots if necessary. The machine may only be refuelled in a well ventilated place. Clean the machine immediately if fuel is spilled.
English – Check operation of chain brake, front hand guard – Correctly mounted guide bar – Correctly tensioned chain – The trigger and trigger lockout must move freely and spring back to the idle position when they are released. – – Master Control lever must move easily to STOP, 0 or † Check that the spark plug boot is secure – a loose boot may cause arcing that could ignite combustible fumes and cause a fire. – Never attempt to modify the controls or safety devices in any way.
English Examine the saw chain periodically at short intervals and as soon as you note any tangible changes: a machine that is not in perfect working order. In case of doubt, have the unit checked by your servicing dealer. – Switch off the engine; wait until the saw chain is stationary – Check condition and secure fitting – Check sharpness Check for correct idling, so that the saw chain stops moving when the throttle trigger is released. Check the idle setting regularly and correct when possible.
English Maintenance and repairs Check that the muffler is in perfect working condition. Always switch off the engine before any repair, cleaning or maintenance work and any work on the chain. Risk of injury if the engine starts inadvertently! Do not use the machine if the muffler is damaged or missing – risk of fire, damage to hearing! The machine must be serviced regularly. Do not attempt any maintenance or repair work not described in the Instruction Manual.
English Kickback occurs if, for example, The most common reactive forces are: kickback, pushback and pull-in. 001BA257 KN Dangers of kickback Kickback can result in fatal cuts. – – The saw chain in the area of the upper quarter of the guide bar nose unintentionally comes into contact with wood or a solid object – e. g.
English Dead wood (brittle, rotten or dead wood) poses a significant, highly unpredictable hazard. It is extremely difficult or even practically impossible to recognise the danger. Use aids such as winches or draglines. be drawn forward toward the log – to avoid this, engage the bumper spike firmly in the wood. Pushback (B) B 001BA038 KN When felling close to roads, rail lines, power lines, etc., work with particular care. If necessary, notify police, power companies or railway authorities.
English Note when reaching the end of a cut that the saw is no longer supported in the kerf. You have to take the full weight of the machine since it might otherwise go out of control. materials, dry plants or scrub. Always contact your local forest authority for information on a possible fire risk. 001BA082 KN When cutting small logs: – Use a sturdy and stable support – sawhorse. Position the saw so that your body is clear of the cutting attachment. – Never hold the log with your leg or foot.
English Ripping cut: 1 1/ 2 21/2 1 001BA088 LÄ 2 001BA151 KN 1 Maintain a distance of at least 2 1/2 tree lengths from the next felling site. 2 N Make relieving cut at the compression side (1) Make bucking cut at the tension side (2) Be wary of pushback when making bucking cut from the bottom upwards (underbuck). NOTICE Do not cut a lying log at a point where it is touching the ground because the saw chain will otherwise be damaged.
English Preparing work area at base of tree B – – 45° A Felling Notch First clear the tree base and work area from interfering limbs and brush to provide a secure footing. Preparing felling notch Clean lower portion of tree base (e.g. with an axe) – sand, stones and other foreign objects will dull the saw chain. C – Establish paths of escape for everyone concerned – opposite to direction of fall at about 45°. – Remove all obstacles from escape paths.
English Determine direction of fall with gunning sight on shroud and fan housing Check direction of fall felling notch to a depth of about 1/10 of trunk diameter. On large diameter trees, cut to no more than width of guide bar. Your chainsaw has a gunning sight on the shroud and fan housing. Use this gunning sight. Making Felling Notch Position the saw so that the felling notch is at a right angle to the direction you want the tree to fall.
English The tree is felled with the felling cut (E). Cut horizontally. – 1/10 (at least 3 cm) of width of hinge (D) higher than bottom of felling notch (C). The holding strap (F) or stabilizing strap (G) supports the tree and helps prevent it from falling prematurely. – Width of strap: about 1/10 to 1/5 of tree diameter. – Do not cut into the strap while making the felling cut. – Leave a broader strap on rotten trees.
English 1. 2. 1. 3. 2. Shout a warning before starting the felling cut. N Start felling cut (E) using plunge-cut method – insert full length of guide bar in the trunk. Engage the spiked bumper behind the hinge and use it as a pivot – avoid repositioning the saw more than necessary. 5. N Insert a felling wedge (3). Shout a second warning immediately before the tree falls. N 001BA263 KN 001BA273 KN 001BA261 KN 4. N 3. Shout a warning before starting the felling cut.
English N Start felling cut using plunge-cut method. Felling Cut with Holding Strap (Leaner) N Enlarge felling cut as far as hinge (4). A) Small diameter trees – Do not cut into the hinge. N Enlarge felling cut as far as stabilizing strap (5). – Do not cut into the stabilizing strap. Perform this felling cut when the tree diameter is smaller than the length of the guide bar. 2. 001BA266 KN 1. Shout a second warning immediately before the tree falls. 6. N Insert a felling wedge (6).
English Continue the felling cut on the other side of the trunk. B) Large diameter trees Make sure the second cut is at the same height as the first cut. 1. 2. N Engage the spiked bumper behind the hinge and use it as a pivot – avoid repositioning the saw more than necessary. N The guide bar nose enters the wood (4) before it reaches the holding strap – hold the saw horizontally and swing it as far as possible. N Enlarge felling cut as far as hinge (5). – Do not cut into the hinge.
English Chain Scabbard Fitting Chain Scabbard Extension A cutting attachment consists of the saw chain, guide bar and chain sprocket. 1 1 – 3 001BA248 KN 2 a – 001BA244 KN The cutting attachment that comes standard is designed to exactly match the chain saw. The pitch (t) of the saw chain (1), chain sprocket and the nose sprocket of the Rollomatic guide bar must match. The drive link gauge (2) of the saw chain (1) must match the groove width of the guide bar (3).
English Releasing the chain brake 3 Removing the chain sprocket cover 001BA186 KN 2 4 1166BA039 KN N N Turn the captive nuts to the left until it hangs loosely in the chain sprocket cover N Pull hand guard towards the front handle until it engages audibly – chain brake is released N Position the guide bar over the bolts (1) – the cutting edges of the saw chain must point to the right N Position the locating hole (2) over the peg of the tensioner slide – simultaneously place the saw chain over
English Tensioning the Chain Checking Chain Tension Fuel Your engine requires a mixture of gasoline and engine oil. Retensioning during cutting work: N Shut off the engine. N Loosen the nuts. N Hold the bar nose up. N Use a screwdriver to turn the tensioning screw (1) clockwise until the chain fits snugly against the underside of the bar. N While still holding the bar nose up, tighten down the nuts firmly. N Go to "Checking Chain Tension".
English Engine Oil If you mix the fuel yourself, use only STIHL two-stroke engine oil or another high-performance engine oil in accordance with JASO FB, JASO FC, JASO FD, ISO-L-EGB, ISO-L-EGC or ISO-L-EGD. STIHL specifies STIHL HP Ultra twostroke engine oil or an equivalent highperformance engine oil in order to maintain emission limits over the machine’s service life.
English N Turn the cap counterclockwise (about a quarter turn). 001BA235 KN 001BA234 KN 001BA232 KN Closing N Fold the grip down so that it is flush with the top of the cap. Grip must be vertical: Fit the cap – marks on tank cap and fuel tank must line up. N Press the cap down as far as stop. 001BA241 KN 001BA234 KN N Marks on tank cap and fuel tank must line up. 001BA233 KN Tank cap is locked. 001BA237 KN N Take care not to spill fuel while fueling and do not overfill the tank.
English Left: 001BA239 KN Right: Bottom of cap is twisted – inner mark (1) in line with outer mark. Bottom of cap in correct position – inner mark is under the grip. It is not in line with the outer mark. N N Continue rotating the cap counterclockwise (about a quarter turn) – this causes the bottom of the cap to be turned to the correct position. Turn the cap clockwise and lock it in position – see section on "Closing".
English Oil pump setting for increased oil delivery rate Checking Chain Lubrication Chain Brake 1166BA034 AM Locking the chain Frequent checking and refilling of the oil tank is necessary – see "Adjusting oil quantity". Refill the chain oil tank when the fuel tank is approximately half empty 143BA024 KN All oil pump settings Take care not to spill chain oil during refilling and do not overfill the tank. STIHL recommends use of the STIHL filling system for chain oil (special accessory).
English The chain brake will operate only if the hand guard has not been modified in any way. Releasing the chain brake Winter Operation Check operation of the chain brake Pre-heat carburetor at temperatures below +10 °C 1 143BA012 KN Chain brake maintenance N Pull the hand guard back toward the front handle, NOTICE Always disengage chain brake before accelerating the engine (except when checking its operation) and before starting cutting work.
English Mounting the cover plate (special accessory) The partial covering of the slits in the fan housing keeps out powdered or drifting snow.
English Setting the Master Control Lever Starting / Stopping the Engine On the ground To move the Master Control lever from the run position F to start }, depress the trigger lockout and the throttle trigger and hold them in that position – set the Master Control lever to start } and let go of the throttle trigger and trigger lockout.
English Between knees or thighs Cranking Starting the Saw 1166BA028 AM Decompression valve N N Hold the rear handle tightly between your legs, just above the knees. Hold the front handle firmly with your left hand – your thumb should be under the handle. 1166BA038 1166BA037 N N Pull the starter grip slowly with your right hand until you feel it engage – and then give it a brisk strong pull and push down the front handle at the same time.
English As soon as the engine runs At very low outside temperatures N N 3 1166BA026 AM 2 1166BA027 AM 1 2 N Stopping the Engine 0 1 If the engine was started in the start position }: Press down trigger lockout and the pull the throttle trigger (2) at the same time – the Master Control lever (1) moves to the run position (F) and the engine settles down to idling speed. Hold your saw firmly. N Pull the starter grip quickly and firmly as often as necessary until the engine starts.
English N Hold the saw on the ground. N Push the Master Control lever as far as stop in direction of STOP or † and hold it there. WARNING An ignition spark may occur if the Master Control lever is not held against STOP or †. N Operate the rewind starter several times. N Release the Master Control lever – it springs back to the run position F. N Install the spark plug – see "Spark Plug". N Hold and start your saw as described.
English Wait for engine to cool down. Keep the machine with a full tank of fuel in a dry place, well away from sources of ignition, until you need it again. Long-term storage See "Storing the machine" Setting for increased oil delivery rate Oil Quantity Control Varying cutting lengths, types of wood and work techniques require varying amounts of oil. 1166BA010 AM Short-term storage Standard setting If necessary, the oil flow can be increased beyond the standard setting.
English Taking Care of the Guide Bar Picco Rapid Rapid 3/8“ P 5.0 mm 3/8“; 0.325“ 6.0 mm 0.404“ 7.
English Wash the filter in STIHL specialpurpose cleaner (special accessory) or a clean, nonflammable cleaning liquid (e.g.
English N Release chain brake. NOTICE If the throttle trigger is released before the chain saw has been fully calibrated, calibration will be aborted. Calibration has to be started again from the beginning. N The engine idles. The chain saw is calibrated and ready for use. Spark Arresting Screen in Muffler N If engine performance deteriorates, check the spark arresting screen in the muffler N Let the muffler cool down Fully depress throttle trigger and hold it there.
English Checking the Spark Plug If the engine is down on power, difficult to start or runs poorly at idle speed, first check the spark plug. N Fit a new spark plug after about 100 operating hours – or sooner if the electrodes are badly eroded. Install only suppressed spark plugs of the type approved by STIHL – see "Specifications". Removing the spark plug Installing the spark plug A N Clean dirty spark plug. N Check electrode gap (A) and readjust if necessary – see "Specifications".
English For periods of 3 months or longer N N N Drain and clean the fuel tank in a well ventilated area. Remove chain sprocket cover, saw chain and guide bar. N Dispose of fuel properly in accordance with local environmental requirements. Release chain brake – pull hand guard against the front handle Fit new chain sprocket Remove the saw chain and guide bar, clean them and spray with corrosion inhibiting oil.
English N N After refitting, turn the clutch drum and/or spur chain sprocket approx.
English File holder Proper sharpening N Select sharpening tools in accordance with chain pitch N Clamp guide bar if necessary N 689BA025 KN Block saw chain – push the hand guard forward N Always use a file holder (special accessory, see table "Sharpening tools") when sharpening saw chains by hand. File holders have markings for the sharpening angle. To advance the saw chain, pull the hand guard toward the handlebar: The chain brake is disengaged.
English N File only from the inside outward N The file only sharpens on the forward stroke – lift the file on the backstroke Do not file tie straps and drive links N Rotate the file a little periodically in order to avoid uneven wear N To remove file burr, use a piece of hardwood N Check angle with file gauge All cutters must be equally long. With varying cutter lengths, the cutter heights also vary and cause rough running of the saw chain and chain breakage.
English WARNING N After sharpening, clean the saw chain thoroughly, removing any filings or grinding dust – lubricate the saw chain thoroughly N In the event of extended periods of disuse, store saw chains in cleaned and oiled condition 689BA052 KN Depth gauges that are too low increase the kickback tendency of the chain saw.
English Complete machine Throttle trigger, throttle trigger lockout, choke lever, choke control, stop switch, master control lever (dependent on equipment) Chain brake Manual fuel pump (if present) Fuel pick-up body / filter in fuel tank Visual inspection (condition, leaks) X Clean Function tests X X X X Check X X Have repaired by a specialist dealer1) X Check X Clean, replace filter insert X X X Fuel tank Clean X Lubricating oil tank Clean X Chain lubrication Check X Check, pa
Air filter X Clean X Cylinder fins Clean X Chain catcher X X X X 2) X Tighten X Have cleaned by a specialist dealer, or replaced if necessary1) Check X X Replace Replace As required If damaged X Replace after 100 hours of operation Safety information label 42 X X X Adjust electrode gap Exhaust bore 2) X If the saw chain rotates in idle, have the chain saw serviced by a servicing dealer1) Decarbonise after 139 hours of operation, subsequently after every 150 hours of operation
English Main Parts 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 # 2 1 # 3 8 4 5 9 10 11 6 8 6 15 14 7 16 17 13 22 20 MS 661 C-M 18 23 1166BA023 AM 21 19 12 Filter cover cap Spark plug boot Handle heating switch (depending on equipment version) Chain brake Chain sprocket Chain sprocket cover Chain catcher Bumper spike Chain tensioner Guide bar Oilomatic saw chain Oil filler cap Muffler Front hand guard Front handle (handlebar) Decompression valve Starter grip Fuel fill
English Specifications Engine STIHL single cylinder two-stroke engine Displacement: Cylinder bore: Piston stroke: Engine power according to ISO 7293: Idle speed:1) 1) 91.1 cm3 56 mm 37 mm 5.4 kW (7.3 HP) at 9500 rpm 2800 rpm to ISO 11681 +/- 50 rpm Ignition system Weight Saw chains 3/8" Dry, without cutting attachment MS 661 C-M 7.4 kg MS 661 C-M with handle heating 7.5 kg Rapid Micro (36 RM) Type 3652 Rapid Super (36 RS) Type 3621 Rapid Super 3 (36 RS3) Type 3626 Pitch: 3/8" (9.
English REACH REACH is an EC regulation and stands for the Registration, Evaluation, Authorisation and Restriction of Chemical substances. For information on compliance with the REACH regulation (EC) No. 1907/2006 see www.stihl.com/reach. Exhaust Emissions The CO2value measured in the EU type approval procedure is specified at www.stihl.com/co2.
English Disposal EC Declaration of Conformity ANDREAS STIHL AG & Co. KG Badstr. 115 D-71336 Waiblingen Observe all country-specific waste disposal rules and regulations. Germany 000BA073 KN declare in exclusive responsibility that the product STIHL products must not be thrown in the garbage can. Take the product, accessories and packaging to an approved disposal site for environmentfriendly recycling. Contact your STIHL servicing dealer for the latest information on waste disposal.
English MS 661 C-M 47
English 48 MS 661 C-M
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