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CM160

CRANKSHAFT

NOTE: If any servicing of the connecting rods,center bearings, or oil-injection pump drive gear isnecessary, Arctic Cat recommends that the crank-shaft be taken to a qualified machine shop for thatservice.

1. Wash the crankshaft with bearings in parts-clean-ing solvent.

2. Inspect the bearings for wear, scoring, scuffing,damage, or discoloration. Rotate the bearings.Bearings must rotate freely and must not bind orfeel rough. If any abnormal condition is noted,replace the bearing.

FC039

3. Inspect the connecting-rod bearings by rotatingthem. The bearings must rotate freely and must notbind or feel rough. If a connecting-rod bearingmust be replaced, the connecting rod and crank pinmust also be replaced.

FC040

4. Inspect the oil-injection pump drive gear for anysigns of worn or chipped teeth. If either conditionexists, replace the gear.

NOTE: Lubricate bearings thoroughly prior toassembly.

REMOVING/INSTALLING OUTER CRANKSHAFT BEARINGS

NOTE: The end bearings are not pressed ontothe crankshaft. The bearings can be removed sim-ply by sliding them off the crankshaft.

CM161

Inspect the crankshaft bearing area for wear. If anywear is noted on either end, replace the crankshaft end.

NOTE: Install the bearings by sliding each bear-ing onto the crankshaft making sure the dowel-pinhole in the outer race is properly positioned andwill align with its hole and pin in the crankcase.

CM161

! CAUTIONWater or parts-cleaning solvent must be used inconjunction with the wet-or-dry sandpaper or dam-age to the sealing surface may result.

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2-112

REED VALVE ASSEMBLY

1. Inspect the reed valves, stoppers, and valve blocksfor cracks or any deterioration.

CM162

2. Wash the reed valves, stopper, and cage assemblyin parts-cleaning solvent and blow dry.

3. Inspect the reed stopper height. Using a caliper,measure the distance from the seat to the bottomouter tip edge of the stopper. Measurement mustnot exceed specifications. If measurement is notwithin specifications, either bend or replace thereed stopper.

CM163

4. Inspect the reed-to-seat clearance. Using a feelergauge, measure the clearance. Clearance must beless than 0.20 mm (0.008 in.). If clearance is notwithin specifications, replace the reed valve.

5. To assemble, place the reed valves on the cagewith its clipped corner positioned to the lowerright hand corner of the cage. Place the reed stop-per assembly into position and secure with thescrews coated with red Loctite #271.

CM164A

Measuring Critical Components

NOTE: Critical engine specifications charts canbe found in Section 1 of this manual.

CYLINDER HEAD VOLUME (Squish-Gap Method)

To check the squish gap, a micrometer and two heavypieces of solder will be needed.

1. Remove the spark plugs from the engine.

2. Simultaneously insert two pieces of solder downthrough the spark plug hole and push them upagainst the inner cylinder bore towards the MAG-side and PTO-side of the cylinder.

3. Pull the recoil rope and crank the engine over sev-eral times while the solder is being held firmly inplace.

4. Remove both pieces of solder from the cylinder.Using the micrometer, measure the very end of thesqueezed solder piece. Record the reading.

NOTE: If the solder hasn’t been squeezed by thepiston, a larger piece of solder must be used.Repeat procedure.

5. Using the opposite end of the solder pieces, insertthem down through the spark plug hole towards thePTO-side and MAG-side of the cylinder. Push onthe solder until they contact the inner cylinder bore.

6. Pull the recoil rope and crank the engine over sev-eral times. Remove both pieces of solder from thecylinder and measure the opposite squeezed endswith a micrometer. Record reading.

NOTE: Measure from PTO to MAG-side of the pis-ton to accurately measure the squish gap. Nevermeasure across piston, exhaust to carburetorside, as the piston will rock and the reading won’tbe accurate.

Readings may vary from side to side.

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2

NOTE: Make sure the smaller reading is 1.5 mm(0.059 in.) or less for the 800 cc or 1.49 mm (0.058in.) or less for the 1000 cc.

CYLINDER TRUENESS

1. Measure each cylinder in the three locations fromfront to back and side to side for a total of six read-ings.

FC044

2. The trueness (out-of-roundness) is the differencebetween the highest and lowest reading. Maxi-mum trueness (out-of-roundness) must not exceed0.1 mm (0.004 in.).

0725-586

PISTON SKIRT/CYLINDER CLEARANCE

1. Measure each cylinder front to back about 2.5 cm(1 in.) from the bottom of each cylinder.

2. Measure the corresponding piston skirt diameter ata point 1 cm above the piston skirt at a right angleto the piston-pin bore. Subtract this measurementfrom the measurement in step 1. The difference(clearance) must be within 0.075-0.0105 mm(0.0029-0.0041 in.).

AC091

PISTON-RING END GAP

1. Place each piston ring in the wear portion above theexhaust port of its respective cylinder. Use the pis-ton to position each ring squarely in each cylinder.

2. Using a feeler gauge, measure each piston-ringend gap. Acceptable ring end gap must be within0.30-0.50 mm (0.012-0.0196 in.).

FC045

PISTON PIN AND PISTON-PIN BORE

1. Measure the piston pin diameter at each end and inthe center. Acceptable piston pin measurementmust be within 21.995-22.000 mm (0.8659-0.8661in.) for the 800 cc or 23.995-24.000 mm (0.9447-0.9449 in.) for the 1000 cc. If any measurementvaries by more than 0.02 mm (0.001 in.), the pis-ton pin and bearing must be replaced as a set.

AN056

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2-114

2. Insert a snap gauge into each piston-pin bore; thenremove the gauge and measure it with a micrometer.The diameter measurement must be within 22.002-22.010 mm (0.8662-0.8665 in.) for the 800 cc or24.002-24.010 mm (0.9450-0.9453 in.) for the 1000cc. Take two measurements to ensure accuracy.

AC092

CONNECTING-ROD SMALL END BORE

1. Insert a snap gauge into each connecting-rod smallend bore; then remove the gauge and measure itwith a micrometer.

AN061

2. The diameter measurement must be within27.003-27.011 mm (1.0631-1.0634 in.) for the 800cc or 29.003-29.011 mm (1.1410-1.1420 in.) forthe 1000 cc.

CRANKSHAFT RUNOUT

0742-727

1. Using the V Blocks, support the crankshaft on thesurface plate.

NOTE: The V blocks should support the crank-shaft on the outer bearings.

2. Mount a dial indicator and base on the surfaceplate. Position the indicator contact point againstthe crankshaft location point A (PTO-end) fromthe crankshaft end. Zero the indicator and rotatethe crankshaft slowly. Note the amount of crank-shaft runout (total indicator reading).

NOTE: For runout location point specifications,see Crankshaft Runout Specifications in Section 1of this manual.

3. Position the indicator contact point against thecrankshaft location point B (MAG-end) from thecrankshaft end. Zero the indicator and rotate thecrankshaft slowly. Note the amount of crankshaftrunout (total indicator reading).

FC046

4. Position the indicator contact point against thecrankshaft at location point C (center). Zero theindicator and rotate the crankshaft slowly. Notethe amount of crankshaft runout (total indicatorreading).

5. If runout exceeds 0.05 mm (0.002 in.) at any of thecheckpoints, the crankshaft must be eitherstraightened or replaced.

Assembling Engine

NOTE: The use of new gaskets and seals is rec-ommended when assembling the engine.

NOTE: Before the engine is assembled, clean thethreads of the cap screws and the threaded areasof the engine where loctite will be used.

NOTE: When the use of a lubricant is indicated,use Arctic Cat Synthetic APV 2-Cycle Oil.

1. Apply a thin coat of grease to the inner seal lips ofthe water pump seal.

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2

2. Using the seal driver, position the inner waterpump shaft seal onto the seal driver and gently tapthe seal down into position.

NOTE: Grease must be applied to the lips of theinner seal before installation.

MS986A

NOTE: The seal must be installed with its springside towards the crankshaft.

3. Install the snap ring securing the inner seal in thecrankcase.

MS415

4. Using the seal driver, carefully install the outerwater pump seal. Gently tap the seal down intoposition until it seats itself against its flange.

MS988

5. Apply a thin coat of grease to the sealing surfaceof the oil-injection pump/water pump driveshaft;then place the Oil Seal Protector Tool at the end ofthe shaft. Twist the driveshaft clockwise as it ispushed through the oil and water pump seals; thenremove the tool.

FS191

6. Position the shim on the oil-injection pump end ofthe driveshaft.

CM159A

7. Secure the upper crankcase half upside-down on asuitable support; then install the C-ring (A), thefour bearing retaining pins (B), and the two crank-case dowel pins (C).

! CAUTIONBe very careful not to damage the seals wheninstalling the oil pump driveshaft. Be certain to usethe seal protector tool. Twist the driveshaft clock-wise as it enters the seal area and while it is beingpushed through the seals.

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2-116

CM165C

8. Place the crankshaft end bearings into positionmaking sure the bearing retaining pin hole is posi-tioned inward.

NOTE: The bearing retaining pin hole is the holethat does not go entirely through the bearing case.

CM043A

9. Lubricate the inner lips of the crankshaft oil sealswith grease; then slide the seals onto the crank-shaft making sure the spring side of each seal facesinward.

NOTE: There is a MAG-side seal and a PTO-sideseal.

10. Apply oil to the crankshaft bearings; then installthe crankshaft into the upper crankcase half. Besure the alignment hole in each bearing is posi-tioned over its respective dowel pin in the crank-case; then seat the crankshaft.

CM045A

NOTE: To check the bearing for proper position,place the point of a sharp tool into the dimplefound in the bearing race. Strike the tool with thepalm of the hand in either direction. If the bearingmoves, it isn’t positioned correctly and must berotated until it drops onto the dowel pin.

11. Position the two center seal rings with their endgaps 180° apart (up on one and down on theother); then apply a thin coat of High-Temp Seal-ant to the entire bottom half of the crankcase seal-ing surface.

CM036A

CM166

NOTE: Use only Arctic Cat High-Temp Sealant toseal the crankcase halves.

12. Assemble the crankcase halves making sure thatthe crankshaft gear and oil-injection pump drive-shaft gears mesh. Rotate the crankshaft one fullturn to align the crankshaft gear and pump drive-shaft.

13. Install the crankcase cap screws securing thecrankcase halves.

14. Tighten cap screws (1-10) in three steps to 31 ft-lbusing the appropriate pattern shown.

! CAUTIONIf the bearings are not properly seated duringassembly, the crankcase halves will not seal tightlyand severe engine damage will result.

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2

742-198A

742-197A

15. On the 800 cc, tighten cap screw (11) to 8 ft-lb;then turn the engine right-side up and tighten capscrews (12-15) in three steps to 25 ft-lb.

16. On the 1000 cc, tighten cap screws (11-13) in threesteps to 25 ft-lb; then turn the engine right side upand tighten cap screw (14) to 8 ft-lb.

NOTE: Secure the connecting rods with rubberhoses.

17. Install the oil-injection pump retainer with a newO-ring.

FC082

18. With the new O-ring in place, install the oil-injec-tion pump making sure the pump shaft slot (A) andpump driven gear shaft (B) align. Secure with twoscrews (coated with blue Loctite #243). Tightenthe two screws to 8 ft-lb.

CM167A

NOTE: For assembly purposes, always use a newO-ring lubricated with oil on the oil injection pump.

19. Install the oil-injection hoses and secure with theclamps; then place the lower union assembly intoposition and secure with new gaskets and unioncap screw. Tighten to 54 in.-lb.

CM153A

20. Secure the intake flanges, reed valve assemblies,and gaskets with cap screws; then in a crisscrosspattern, tighten to 8 ft-lb.

21. Install the coolant temperature sensor and tightensecurely; then secure the sensor wire to the sensorwith a cable tie.

800 cc

1000 cc

! CAUTIONBe sure the oil-injection pump/water pump drive-shaft is properly aligned with the slot of the oil-injec-tion pump. The pump will be damaged if these twocomponents are not aligned.

! CAUTIONAlways use new gaskets and assure that a gasket isin place on each side of the union prior to securingthe union cap screw to the crankcase.

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2-118

CM172

22. Position the ceramic/rubber seal into the back sideof the water pump impeller with the ceramic faceof the seal directed out.

CM168

23. Using both thumbs, press the seal into positionmaking sure its marked side is positioned towardsthe rubber seal cup; then apply a thin coat ofgrease to the seal outer surface.

CM169

24. Place the impeller into position and secure with acap screw and washer. Be sure the rubber side ofthe washer is lubricated with a light coat of greaseand directed toward the impeller. Apply blue Loc-tite #243 to the threads of the cap screw andtighten to 8 ft-lb.

25. Apply high-temperature sealant to the crankcase/water pump cover seam; then install the dowelpins into the crankcase.

CM171A

NOTE: Sealant is only required on the crankcaseseam.

CM171B

26. Apply a thin film of low-temp grease to the waterpump cover O-ring; then position the O-ring intothe water pump cover. With the alignment pins inplace, install the cover. Secure with seven screwsusing the pattern shown. Tighten to 8 ft-lb.

0742-257

27. With the bypass valve of the thermostat directed tothe 12 o’clock position, install the thermostat andhousing; then in a crisscross pattern, tighten thecap screws to 8 ft-lb.! CAUTION

The rubber side of the washer, which secures theimpeller, must be positioned toward the impeller. Ifinstalled incorrectly, a coolant leak will result.

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CM157A

CM155A

28. Install the dowel pins into the crankcase; thenplace the cylinder base gasket into position on thecrankcase.

29. Install the piston rings on each piston so the letteron the top (inclined surface) of each ring faces thedome of the piston.

726-306A

30. Apply oil to the connecting-rod small end bear-ings; then install the small-end bearings. Install awasher on each side of the connecting rod.

NOTE: The shoulder side of the washer mustseat to the needle bearing.

CM172A

31. Place each piston over the connecting rod so theindicator dot on each piston will point toward theintake/exhaust ports; then secure with an oiled pis-ton pin.

NOTE: The indicator dot is found on the pistondome.

CM173

32. Install the new circlips so the open end is directedeither up or down.

CM174

33. Rotate each piston ring until the ring ends areproperly positioned on either side of the ringkeeper; then apply oil to the piston assemblies andcylinder bores. Remove the rubber hoses from theconnecting rods.

! CAUTIONIncorrect installation of the piston rings will result inengine damage. ! CAUTION

Make sure the circlips are firmly seated and the openend is directed either up or down before continuingwith assembly.

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2-120

34. In turn on each cylinder, place a piston holder (orsuitable substitute) beneath the piston skirt andsquare the piston in respect to the crankcase; thenusing a ring compressor or the fingers, compressthe rings and slide the cylinder over the piston.Remove the piston holder and seat the cylinderfirmly onto the crankcase.

NOTE: The cylinders should slide on easily. DONOT force the pistons into the cylinders.

CM148

35. Secure each cylinder by installing the four nutsand four new cap screws. DO NOT TIGHTEN ATTHIS TIME.

36. Apply a thin coat of high-temperature siliconesealant to each exhaust port; then install theexhaust gaskets.

37. Apply a thin coat of high-temperature siliconesealant to the mating surfaces of the exhaust mani-fold; then install the exhaust manifold and securewith the eight nuts. Tighten the nuts using the pat-tern shown to 17 ft-lb.

0742-292

NOTE: Always use new cap screws when install-ing the cylinders.

38. Secure the cylinders (from step 35) by tighteningthe cylinder base nuts and cap screws to 42 ft-lb inthree steps using the appropriate pattern shown.

0738-206

0738-220

39. Install the two cylinder O-rings on the top of eachcylinder making sure they are correctly positionedin the grooves.

FC077

NOTE: Lubricating the cylinder O-rings with alight coat of grease will help keep them seated inthe grooves of the cylinder.

40. Place new O-rings onto each of the head capscrews. Place four of these cap screws (from oppo-site end of each other) into the cylinder head.Thread the spark plugs in part way; then whileholding the head above the cylinder, carefully startand finger-tighten all four cap screws whileobserving the cylinder O-rings to make sure theyremain in position. Slowly place the head intoposition on top of the O-rings.

800 cc

1000 cc

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