SERVICE MANUAL HUSQVARNA

HUSQVARNAModel

61, 61 CB, 61 Rancher,162 SE, 162 SG

66, 266, 266 CB,266 SG, 266 XP,268, 268 XP

272 XP, 272 XPG

MAINTENANCE

Boremm (in.)

48.0(1.89)

50.0(1.97)52(2.05)

Strokemm (in.)

34.0(1.34)

34.0(1.34)34.0

(1.34)

accelerating, adjust idle

Displacementcc (cu. in.)

61.5(3.75)

66.7(4.1)72

(4.4)

mixture screw LU

DriveType

Direct

Direct

Direct

BRICAT

SPARK PLUG. Recommendedspark plug is Bosch WS7F or ChampionRCJ7Y. Electrode gap should be 0.5 mm(0.020 in.).

CARBURETOR. A Tillotson ModelHS diaphragm carburetor is used on allmodels except Model 61, which may beequipped with a Tillotson HS or a Wal-bro WS carburetor. Ref sr to Tillotson orWalbro section of CARBURETORSERVICE section for carburetor over-haul and exploded vievrs.

On 268XP and 272XP models, initialadjustment of low- and high-speed mix-ture needles is one turn open. On allother models, initial adjustment oflow-speed mixture needle is one turnopen and high-speed mixture needle is3/4 turn open. On all models, make fi-nal adjustment with engine warm andrunning.

Turn low-speed mixture needle (L-Fig. H40) clockwise tci obtain highestidle speed, then turn screw 1/4 turncounterclockwise. Engine should accel-erate cleanly without hesitation. If en-gine stumbles or seems sluggish when

xintil engine accelerates without hesita-tion.

Adjust high-speed mixture needle(H) to obtain optimum performance un-der cutting load. Make certain engineno-load speed (bar and chain installed)does not exceed 12,000 rpm on Models61, 66 and 162, or 12,500 rpm on Mod-els 266, 268 and 272.

Do not operate saw with high-speedmixture too lean because engine dam-age may result from lack of lubricationand overheating.

Adjust idle speed stop screw (T) soengine idles just below clutch engage-ment speed.

IGNITION. All models are equippedwith an electronic breakerless ignitionsystem. Ignition timing is not adjust-able and no periodic maintenance is re-quired. Air gap between ignition coiland flywheel should be 0.30 mm (0.012in.).

Fig. H40—Vlew showing foi-satlon of carburetoradjuatingpolnta typical of a'l modala. Mle apeadacraw la at (T), idla mixture acraw la at (L) and

high apaad mlxtura azraw la at (H).

Fig, H41—Vtew ahowlng location of oil pump ad-Juating acraw (S}. Adjuatlng acraw ahown la aat at

poaltlon 2.

bricated by mixing oil with the fuel.Recommended fuel:oil ratio is 50:1when using Husqvama Two-Stroke Oil.If Husqvarna Two-Stroke Oil is notavailable, use good quality oil designedfor use in air-cooled two-stroke enginesmixed at 25:1 ratio.

All models are equipped with an ad-justable automatic chain oil pump. Ad-jus tment is possible after clutchremoval. Turn adjusting screw (S-Fig.H41) for desired oil output; positionnumber "1" is minimum output, posi-tion number "4" is maximum output.

REPAIRS

CRANKCASE PRESSURE TEST.An improperly sealed crankcase cancause the engine to be hard to start, runrough, have low power and overheat.Refer to ENGINE SERVICE section ofthis manual for crankcase pressure testprocedure. If crankcase leakage is indi-cated, pressurize crankcase and use asoap and water solution to check gas-kets, seals, pulse line and castings forleakage.

TIGHTENING TORQUE. Refer tothe following table when tightening fas-teners.Carburetor-

61, 66, 162 4-6 N-m(35-53 in.-lbs.)

266, 268, 272 2-3 N-m(18-26 in.-lbs.)

Crankcase screws 7-9 N«m(62-79 in.-lbs.)

Cylinder screws 8-10 N»m(71-88 in.-lbs.)

Clutch hub 30-40 N-m(22-29 ft.-lbs.)

Flywheel nut 30-40 N-m(22-29 ft.-lbs.)

Dlustrations couitesy Husqvama F(»est .& Garden Co. 249

HUSQVARNA CHAIN SAW

Muffler 7-8 N-m(62-70 in.-lbs.)

Oil pump 3-4 N«m(26-35 in.-lbs.)

Spark plug 20 N-m(15ft.-lbs.)

4 mm screw 4.5-5.5 N«m(40-50 in.-lbs.)

5 mm screw 5.5-6.8 N«m(50-60 in.-lbs.)

6 mm screw 10-11.8 N*m(90-105 in.-lbs.)

8 mm screw 28.2-32.8 N-m(250-290 in.-lbs.)

10 mm screw 36.7-42.4 N-m(325-375 in.-lbs.)

PISTON, PIN, RINGS ANDCYLINDER. To disassemble, removecylinder cover and air filter assembly.Disconnect carburetor linkage and fuelline. Remove screws attacbing mufflerbracket to crankcase. Remove cylindermounting screws and lift cylinder withmuffler and carburetor from crankcase.Remove piston pin retaining rings (5-Fig. H42) and pusb piston pin out ofpiston. Remove carburetor and mufflerfrom cylinder.

Clean carbon from cylinder ports andpiston. Inspect cylinder and piston for

Fig. H42—Exploded view of engine componentstypicai of all models.

1. Cylinder2. GaBket3. Piston ring4. Rston5. Pin retainer

6. Bearing7. Crankshaft &

connecting rod assy8. Roller bearing

Fig. H4S—Arrows showing iocation of piston andcyiinder letter grades. Be sure arrow stamped inpiston crown points toward exhaust port when in-

stalling piston. Grade "B" Is shown.

excessive wear or damage. Slight scuff-ing of piston and cylinder wall may bepolished out using fine emery cloth.

On Models 266XP, 268XP and 272XP,new cylinder is available only with a fit-ted piston, but new piston is availableseparately for installation in used cyl-inder. On all other models, piston andcylinder are graded with a letter ac-cording to size. Piston is marked on pis-ton crown while cylinder is marked ontop as shown in Fig. H43. Letter sizesrange from "A" to "C," with "A" beingthe smallest size. Piston cylindergrades should match, although one sizelarger piston may be installed in a usedcylinder. For instance, a piston graded"C** may be used in a cylinder graded

Piston must be installed with arrowon piston crown pointing toward ex-haust port. Refer to Fig. H43. A locatingpin is present in piston ring groove toprevent piston ring rotation. Be surering end gap is positioned around thelocating pin when installing cylinder.Lubricate roller bearing (8-Fig. H42)and piston with oil before installing cyl-inder. Tighten cylinder mountingscrews evenly to 8-10 N*m (71-88in.-lbs.).

CRANKSHAFT, CONNECTINGROD AND CRANKCASE. Ib disas-semble, remove chain and guide bar,cylinder cover, air filter assembly,starter assembly and air baffle. Re-move spark plug and install a pistonstop in spark plug hole. Remove fly-wheel mounting nut (right-handthreads) and starter pawls. Use suit-able puller to remove flywheel.

Remove ignition module and genera-tor coil if so equipped. Remove clutchassembly (left-hand threads) and oilpump. Remove cylinder mountingscrews and pull cylinder off piston.Separate piston from connecting rod.Separate tank and handle assemblyfrom crankcase.

Remove crankcase mounting screwsand use Husqvama tool 502 51 61-01,or other suitable puller tool, to separatecrankcase halves and press crankshaftout of main bearings. It will be neces-sary to heat crankcase halves to removeand install main bearings. Care shouldbe taken not to damage mating surfacesof crankcase halves.

Crankshaft and connecting rod are aunit assembly. Check rotation of con-necting rod around crankpin and renewcrankshaft unit if roughness or otherdamage is found. The connecting rodshould not have any radial clearance(up and down play) on the crankpin.

To reassemble, reverse the disassem-bly procedure. Heat crankcase halvesand position tool 502 50 30-04 againstoutside face of crankcase half, thenpress main bearing in from insidecrankcase until bearing bottomsagainst tool. Be sure crankshaft is snugagainst the main bearings and centeredin crankcase. Tighten crankcase screwsevenly, starting with screws closest tocrankshaft, to 7-9 N-m (62-79 in.-lbs.).

CLUTCH. All models are equippedwith a three-shoe centrifugal clutch(Fig. H44), which is accessible after re-moving chain brake assembly andchain guide bar. Clutch hub has left-hand threads (turn clockwise to re-move).

Inspect clutch shoes (1), drum (2) andbearing (3) for excessive wear or dam-age due to overheating. Renew clutchshoes if there is less than 1 mm (0.039in.) of clutch material remaining at themost worn section. Shoes must be re-newed as a set. Inspect chain sprocketteeth for excessive wear and renew asnecessary.

Lubricate the needle bearing withgrease. Tighten clutch hub to 30-40N-m (22-29 ft.-lbs.).

OIL PUMR All models are equippedwith an automatic oil pump, which is

250 Illustrations courtesy Husqvama Forest & Garden Co.

SERVICE MANUAL

1

HUSQVARNA

Fig. H44—Expioded view of two different atyies ofclutch assembiies. Notches on back of dutchdrum (2) engage dogs on oil pump drive gear (4}.1. Hub & shoes2. Clutch drum 4. Oil pump drive gear3. Bearing 5. Washer

6 7 8 9 10 11

Fig. H45—Exploded view of automatic oil pump.When aasembling, note location of braaa and

steel waahera (t and 7}.1. Pump housing2. Oil seal3. Screw4. Adjusting screw5. Pin6. Brass washer7. Steel washer8. Spring9. Driven gear

10. Screw

11. Plunger12. Washer13. Spring14. Washer15. -E" ring16. "O" ring17. Oil tube16. Seal19. Oil hose20. Oil pickup

driven by the clutch diiim. Notches onthe back ofthe clutch dinim engage dogson oil pump drive gesir (4—Fig. H44)which rides on the crankshaft. The oilpump drive gear engages driven gear(9-Fig. H45) which is secured to

Fig. H46—Exploded view ofrewind starter.

1.2.3.4.5.6.7.8.9.

SpringWasherPawlPinRope pulleyRope guideRewind springStarter housingScrew

plunger (11) by set screw (10). Oil pumpoutput is adjusted by turning screw (4).

To remove oil pump, first removeguide bar, clutch and oil pump mount-ing screws. Using two screwdrivers, in-sert blade tips into notches provided inpump housing and carefully withdrawoil pump.

To disassemble for cleaning and in-spection, remove "E" ring (15), washers(12 and 14) and spring (13), Remove ad-justing screw (4). Remove set screw (10)and withdraw plunger (11), driven gear(9), spring (8) and washers (6 and 7).

Lubricate parts with oil during as-sembly. Be sure steel washer (7) is clos-est to spring (8). Install new oil seal (2)and "Oaring(16).

To reinstall, it is recommended thatsleeve, tool number 50 25 053-01, beplaced over crankshaft end to preventdamage to oil seal (2). Tighten pumpmounting screws to 3-4 N-m (27-35in.-lbs.).

REWIND STARTER. To disassem-ble rewind starter, remove starterhousing from saw. Pull starter rope andhold rope pulley (5-Fig. H46) withnotch in pulley adjacent to rope outlet.Pull rope back through outlet so it en-gages notch in pulley and allow pulleyto slowly unwind. Unscrew pulley re-taining screw (9) and carefully removerope pulley. If rewind spring (7) must beremoved, care should be taken not to al-low spring to uncoil uncontrolled.

Install rewind spring in starter hous-ing with spring coiled in clockwise di-rection from outer spring end. Wrapstarter rope around rope pulley in aclockwise direction as viewed with pul-ley in starter housing. TUm rope pulleytwo turns clockwise before passing ropethrough rope outlet to place tension onrewind spring. Spring tension is correct

if rope pulley can be rotated approxi-mately 1/4 turn further when rope is atits greatest length.

When installing starter assembly onsaw, make sure starter pulley properlyengages pawls on flywheel before tight-ening retaining cap screws.

CHAIN BRAKE. Some models maybe equipped with a chain brake systemdesigned to stop chain movementshould kickback occur. Several types ofchain brake systems have been used.Refer to Fig. H47, Fig. H48 and Fig.H48A for exploded views of differentstyles of brake mechanisms used.

The chain brake is activated eitherby the operator's hand striking thehand guard (1) or by sufficient force be-ing applied to the guide bar tip duringkickback to cause the front handle tocontact trigger lever (6-Fig. H47) onearly models, trigger button (9-Fig.H48) or trigger assembly (4-Fig. H48A)on later models, resulting in automaticactivation of brake mechanism.

To adjust chain brake on early mod-els, pull back brake lever and be suremechanism is cocked. TUm adjustingscrew (2-Fig. H47) in until chain can-not be pulled around bar, then turnscrew out approximately four turns. Ifscrew has a square head, be sure screwhead does not rest on hand guard sideplates. Chain should rotate freelyaround bar.

Check brake band tension adjust-ment by starting saw running at wideopen throttle, then manually engagechain brake. Chain should stop rotatingimmediately.

Adjust gap between trigger lever(6-Fig. H47) and trigger arm (10) sochain brake will automatically activatewhen a 6.2-9.8 N (1.4-2.2 lbs.) force isapplied on guide bar tip. A suitable

niustrations courtesy Husqvama Forest & Ganlen Co. 251

HUSQVARNA CHAiri SAW

11

Fig. H47—Exploded viow ofearly model chain brake.

1. Chain brake lever2. Adjusting screw3. Washer4. Spring5. Pin6. Trigger lever7. Spring8. Pin9. Pin

10. Trigger arm11. Front handle12. Side cover13. Spring14. Brake rod & band15. Rivet16. Chain guard

12 13 14

1317

Fig. H48—Exploded view ofiate style chain brake usedon some models. Some mod-els may have adjustable typebrake ttand as shown In In-

set

1. Hand guard2. Cap screw3. TVunnion4. Nut5. Latch6. Bushing7. Rivet8. Spring9. Trigger button

10. Trigger lever11. Spring12. Pin13. Housing14. Guide15. Brake band16. Pin17. Chain guard18. Pin

Spring balance should be used for test-ing and adjustment.

To adjust chain brake on later modelsequipped with brake mechanism shownin Fig. H48, first pull back hand guardand be sure mechanism is cocked, thendetermine if brake system has an ad-justable brake band as shown in insetofFig. H48.

If brake band is adjustable, followearly model brake band adjustmentprocedures as outlined in previousparagraph. On models without adjust-able brake band, be sure spring retain-ing nut (4) is tight against its seat.

On all models, gap between triggerbutton (9) and front handle should beadjusted so chain brake will automati-cally activate when a 6.2-9.8 N (1.4-2.2lbs.) force is applied on guide bar tip. Asuitable spring balance should be usedfor testing and adjustment.

No adjustment is required for chainbrake shown in Fig. H48A.

HANDLE HEATER. Models 162SG,266SG and 272XPG are equipped witha front and rear handle heating system.A generator coil (4-Fig. H49) located

Fig. H48A—Exploded view of lateststyle chain brake mechanism used on

some models.

1. Hand guard2. Retainer3. Pin4. Trigger assy.5. Brake spring6. Brakeband7. PinS. PiD9. Spring

10. Pivot sleeves11. Sawdust guard12. Brake housing13. Chain tension adjusting bolt14. Brake cover

2 3

Fig. H49—Exploded view of ignition system. Gen-erator coii (4) for heated handles is used on

Models 162SG and 266SG.

1. Ignition coil 4. Generator coil2. "O" ring 5. Flywheel3. Seal & retainer 6. Ignition module

252 Illustrations courtesy Husqvama Forest & Garden Co.

SERVICE MANUAL HUSQVARNA

Fig. HSO—ScfmmatIc drawing of handle beatingayatem uaed on aome modela. Refer to text for

bating pmcoduroa.1. Front handle element2. Generator

3. Switch4. Rear handle elements

underneath the flywheel produces ap-proximately 20 volts at 8500 rpm toprovide an electrical current to heatingcoils in front and rear handles.

On some models» a thermostat thatcloses at approximately 10 degrees C(50 degrees F) regulates the heatingsystem. On other models, a switch lo-cated next to the rear handle controlsthe heating system.

An ohmmeter may be used to checkresistance of heating elements. Tb testrear handle elements (4-Fig. H50), con-nect ohmmeter test leads betweenpoints "D'' and **B,'' and "D" and "C."Meter reading should be 0.7-0.9 ohmsfor each element.

Ib test both rear and front handleelements, connect ohmmeter test leadsbetween points "A" and "B." Meterreading should be 5.1-5.7 ohms. If read-ings are significantly higher or lower,check for corroded connections or bro-ken wires.

Tb check generator output, connectvoltmeter between point "A" and crank-case (ground). With heater switchturned "ON" and saw running at about10,000 rpm, meter reading should beabout 20 volts. If there is low or no volt-age, check generator windings for openor short circuit, loss of magnetism orfaulty wiring.

Illustrations courtesy Husqvama Forest & Oaiden Co. 253