Engine Mechanical: Other Suzuki Aerio I

Compression Check

Check compression pressure on all 4 cylinders as follows

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1. Warm up engine.
2. Stop engine after warming up. NOTE: After warming up engine, place transmission gear shift lever in "Neutral" (shift selector lever to "P" range for A/T model), and set parking brake and block drive wheels.
3. Remove engine cover referring to «ENGINE COVER REMOVAL AND INSTALLATION»(ref-251061-S38205840632007032000000) .
4. Disconnect ignition coil couplers.
5. Disconnect ignition coils (1).
6. Remove all spark plugs (2).
7. Disconnect fuel injector wire harness at the coupler.
8. Install special tool (Compression gauge) into spark plug hole. Special Tool 09915-64510-001 09915-64510-002 09915-64530 09915-67010
9. Disengage clutch (to lighten starting load on engine) for M/T vehicle, and depress accelerator pedal all the way to make throttle fully open.
10. Crank engine with fully charged battery, and read the highest pressure on compression gauge. NOTE: For measuring compression pressure, crank engine at least 250 RPM by using fully charged battery. Compression pressure Standard: 1400 kPa (14.0 kg/cm 2 , 199.0 psi) Limit: 1200 kPa (12.0 kg/cm 2 , 170.0 psi) Max. difference between any two cylinders: 100 kPa (1.0 kg/cm 2 , 14.2 psi)
11. Carry out Steps 8 ), 9 ) and 10 ) on each cylinder to obtain 4 readings.
12. After checking, install spark plugs (2) and ignition coils (1).
13. Install ignition coil couplers.
14. Connect injector wire harness at coupler.
15. Install engine cover referring to «ENGINE COVER REMOVAL AND INSTALLATION»(ref-251061-S38205840632007032000000) .

Engine Vacuum Check

The engine vacuum that develops in the intake line is a good indicator of the condition of the engine. The vacuum checking procedure is as follows

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1. Warm up engine to normal operating temperature and make sure that engine idle speed is within specification. NOTE: After warming up engine, place transmission gear shift lever in "Neutral" (shift selector lever to "P" range for A/T model), and set parking brake and block drive wheels.
2. Stop engine and remove engine cover referring to «ENGINE COVER REMOVAL AND INSTALLATION»(ref-251061-S38205840632007032000000) .
3. Disconnect vacuum hose between vacuum pipe (2) and intake manifold (1) from vacuum pipe.
4. Connect special tools (vacuum gauge and hose joint) to vacuum hose of intake manifold side. Special Tool 09915-67311 09918-08210 09355-35754-600 Hose, SUZUKI GENUINE PARTS 09367-04002 3-way joint, SUZUKI GENUINE PARTS
5. Start engine and run engine at specified idle speed (Refer to «IDLE SPEED / IDLE AIR CONTROL (IAC) DUTY INSPECTION»(ref-251058-S10907683132007032000000) ), and read vacuum gauge. Vacuum should be within specification. Vacuum specification 52.6 - 65.8 kPa (40 - 50 cmHg, 15.7 - 19.7 in.Hg) at specified idle speed
6. After checking, remove special tools.
7. Connect vacuum hose to vacuum pipe.
8. Install engine cover referring to «ENGINE COVER REMOVAL AND INSTALLATION»(ref-251061-S38205840632007032000000) .

Cleaning

Blow off dust by compressed air from air outlet side of element.

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1. Remove air cleaner outlet hose (1).

Throttle Body Cleaning

Reference: THROTTLE BODY REMOVAL AND INSTALLATION

Clean passages by blowing compressed air.

Scheme 139

Clean

Clean sealing surface on timing chain cover, crank case, cylinder block and cylinder head.

Remove oil, old sealant, and dust from sealing surface.

Timing Chain Guide No. 2

Check shoe for wear or damage.

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Camshaft Sprocket

Check teeth of sprocket for wear or damage.

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Timing Chain

Check timing chain for wear or damage.

Tensioner Adjuster No. 2

Check shoe (1) for wear or damage and latch functions properly.

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Timing Chain Guide No.1

Check shoe for wear or damage.

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Timing Chain Tensioner

Check shoe (1) for wear or damage.

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Crankshaft Timing Sprocket

Check teeth of sprocket for wear or damage.

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Idler Sprocket

Check teeth and bush (1) of sprocket for wear or damage.

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1st Timing Chain

Check timing chain for wear or damage.

Timing Chain Tensioner Adjuster No. 1

Check that latch (1) and tooth surface (2) are free from damage and latch functions properly.

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Cam Wear

Using a micrometer, measure cam height. If measured height is below its limit, replace camshaft.

Cam height

CAM HEIGHT STANDARD LIMIT

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Camshaft Runout

Set camshaft between two "V" blocks, and measure its runout by using a dial gauge.

If measured runout exceeds the specified limit, replace camshaft.

Runout limit

0.03 mm (0.0012 in.)

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Camshaft Journal Wear

Check camshaft journals and camshaft housings for pitting, scratches, wear or damage.

If any malcondition is found, replace camshaft or cylinder head with housing. Never replace cylinder head without replacing housings.

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Check clearance by using gauging plastic. Checking procedure is as follows.

Scheme 153

1. Clean housings and camshaft journals.
2. Make sure that all valve lash adjusters are removed and install camshaft to cylinder head.
3. Place a piece of gauging plastic to full width of journal of camshaft (parallel to camshaft).
4. Install camshaft housing.
5. Tighten camshaft housing bolts in such order as indicated in figure a little at a time till they are tightened to specified torque. (Scheme 150) NOTE: Do not rotate camshaft while gauging plastic is installed. Tightening torque Camshaft housing bolt a: 11 N.m (1.1 kg-m, 8.0 lb-ft)
6. Remove housing, and using scale (2) on gauging plastic envelop (1), measure gauging plastic width at its widest point. Journal clearance STANDARD LIMIT Standard Limit 0.020 - 0.074 mm (0.0008 - 0.0029 in.) 0.12 mm (0.0047 in.)

If measured camshaft journal clearance exceeds limit, measure journal (housing) bore and outside diameter of camshaft journal.

Replace camshaft or cylinder head assembly whichever the difference from specification is greater.

Camshaft journal

STANDARD ITEM

Scheme 154

Wear of Hydraulic Valve Lash Adjuster

Check adjuster for pitting, scratches, or damage.

If any malcondition is found, replace.

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Measure cylinder head bore and adjuster outside diameter to determine cylinder head-to-adjuster clearance. If clearance exceeds limit, replace adjuster or cylinder head.

Cylinder head bore and adjuster outside diameter

STANDARD ITEM LIMIT

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Oil Relief Valve

Check oil relief valve for clogging and ball for being stuck.

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Valve Guides

Using a micrometer and bore gauge, take diameter readings on valve stems and guides to check stem-to-guide clearance.

Be sure to take reading at more than one place along the length of each stem and guide.

If clearance exceeds limit, replace valve and valve guide.

Valve stem and valve guide

STANDARD ITEM LIMIT

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1. Remove all carbon from valves.
2. Inspect each valve for wear, burn or distortion at its face and stem and, as necessary, replace it.
3. Measure thickness (1) of valve head. If measured thickness exceeds limit, replace valve. Valve specification STANDARD ITEM LIMIT Item Standard Limit In 1.0 mm (0.039 in.) 0.6 mm (0.024 in.) Ex 1.2 mm (0.047 in.) 0.7 mm (0.028 in.)
4. Inspect valve stem end face for pitting and wear. If pitting or wear is found there, valve stem end may be resurfaced, but not so much as to grind off its chamber. When it is worn out so much that its chamber is gone, replace valve.
5. Check each valve for radial runout with a dial gauge and "V" block. To check runout, rotate valve slowly. If runout exceeds its limit, replace valve. Limit on valve head radial runout 0.08 mm (0.003 in.)
6. Seating contact width: Create contact pattern on each valve in the usual manner, i.e., by giving uniform coat of marking compound to valve seat and by rotatingly tapping seat with valve head. Valve lapper (tool used in valve lapping) must be used. Pattern produced on seating face of valve must be a continuous ring without any break, and the width of pattern must be within specified range. Standard seating width revealed by contact pattern on valve face Intake: 0.9 - 1.1 mm (0.0355 - 0.0433 in.) Exhaust: 1.1 - 1.3 mm (0.0433 - 0.0512 in.)
7. Valve seat repair: A valve seat not producing a uniform contact with its valve or showing width of seating contact that is out of specified range must be repaired by regrinding or by cutting and regrinding and finished by lapping. VALVE SEAT: Use valve seat cutters (1) to make three cuts as illustrated in figure. Three cutters must be used: the 1st for making 30° angle, the 2nd for making 60° angle, and 3rd for making 45° angle. The 3rd cut (45°) must be made to produce desired seat width. Seat width for intake valve seat 0.9 - 1.1 mm (0.0355 - 0.0433 in.) Seat width for exhaust valve seat 1.1 - 1.3 mm (0.0433 - 0.0512 in.) VALVE LAPPING: Lap valve on seat in two steps, first with coarse size lapping compound applied to face and the second with fine-size compound, each time using valve lapper according to usual lapping method.

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1. Remove all carbon from combustion chambers. NOTE: Do not use any sharp-edged tool to scrape off carbon. Be careful not to scuff or nick metal surfaces when decarbonizing. The same applies to valves and valve seats, too.
2. Check cylinder head for cracks in intake and exhaust ports, combustion chambers, and head surface at a total of 6 locations. If distortion limit is exceeded, correct gasketed surface with a surface plate and abrasive paper of about #400 (Waterproof silicon carbide abrasive paper): Place paper on and over surface plate, and rub gasketed surface against paper to grind off high spots. Should this fail to reduce thickness gauge readings to within limit, replace cylinder head. Leakage of combustion gases from this gasketed joint is often due to warped gasketed surface: such leakage results in reduced power output. Limit of distortion 0.05 mm (0.002 in.)
3. Distortion of manifold seating faces: Check seating faces of cylinder head for manifolds, using a straightedge and thickness gauge, in order to determine whether these faces should be corrected or cylinder head replaced. Limit of distortion 0.10 mm (0.004 in.)

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1. Referring to data, check to be sure that each spring is in standard condition, free of any evidence of breakage or weakening. Remember, weakened valve springs can cause chatter, not to mention possibility of reducing power output due to gas leakage caused by decreased seating pressure. Valve spring free length STANDARD ITEM LIMIT Standard Limit 44.29 mm (1.7437 in.) 42.60 mm (1.6772 in.) Valve spring preload STANDARD ITEM LIMIT Standard Limit 22.3 - 25.6 kg for 33.8 mm (49.2 - 56.4 lb / 1.33 in.) 24.0 kg for 33.8 mm (52.91 lb / 1.33 in.)
2. Spring squareness: Use a square and surface plate to check each spring for squareness in terms of clearance between end of valve spring and square. Valve springs found to exhibit a larger clearance than limit must be replaced. Valve spring squareness limit 2.0 mm (0.079 in.)

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Cylinder

1. Inspect cylinder walls for scratches, roughness, or ridges which indicate excessive wear. If cylinder bore is very rough or deeply scratched, or ridged, rebore cylinder and use over size piston.
2. Using a cylinder gauge, measure cylinder bore in thrust and axial directions at two positions as shown in figure. If any of following conditions is noted, rebore cylinder.

Scheme 172

1. Cylinder bore diameter exceeds limit.
2. Difference of measurements at two positions exceeds taper limit.
3. Difference between thrust and axial measurements exceeds out-of-round limit. Cylinder bore diameter limit 90.050 mm (3.5433 in.) Taper and out-of-round limit 0.10 mm (0.004 in.) NOTE: If any one of four cylinders has to be rebored, rebore all four to the same next oversize. This is necessary for the sake of uniformity and balance.

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1. Inspect piston for faults, cracks or other damages. Damaged or faulty piston should be replaced.
2. Piston diameter: As indicated in figure, piston diameter should be measured at a position 27.5 mm (1.08 in.) ("a") from piston skirt end in the direction perpendicular to piston pin. Piston diameter PISTON DIAMETER REFERENCE Standard 89.970 - 89.990 mm (3.5422 - 3.5429 in.) Oversize: 0.50 mm (0.0196 in.) 90.470 - 90.490 mm (3.5619 - 3.5626 in.)
3. Piston clearance: Measure cylinder bore diameter and piston diameter to find their difference which is piston clearance. Piston clearance should be within specification as follows. If it is out of specification, rebore cylinder and use oversize piston. Piston clearance 0.02 - 0.04 mm (0.0008 - 0.0015 in.) NOTE: Cylinder bore diameters used here are measured in thrust direction at two positions.
4. Ring groove clearance: Before checking, piston grooves must be clean, dry and free of carbon. Fit new piston ring (1) into piston groove, and measure clearance between ring and ring land by using thickness gauge (2). If clearance is out of specification, replace piston. Ring groove clearance Top: 0.03 - 0.07 mm (0.0012 - 0.0027 in.) 2nd: 0.02 - 0.06 mm (0.0008 - 0.0023 in.)

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1. Check piston pin, connecting rod small end bore and piston bore for wear or damage, paying particular attention to condition of small end bore bush. If pin, connecting rod small end bore or piston bore is badly worn or damaged, replace pin, connecting rod or piston.
2. Piston pin clearance: Check piston pin clearance in small end. Replace connecting rod if its small end is badly worn or damaged or if measured clearance exceeds limit. Piston pin clearance in small end (standard) 0.003 - 0.014 mm (0.0001 - 0.0005 in.) Small-end bore 21.003 - 21.011 mm (0.8269 - 0.8272 in.) Piston pin diameter 20.997 - 21.000 mm (0.8267 - 0.8268 in.)

Piston rings

To measure end gap, insert piston ring (2) into cylinder bore and then measure the gap by using thickness gauge (1).

If measured gap is out of specification, replace ring.

Note. Clean carbon and any other dirt from top of cylinder bore before inserting piston ring.

Piston ring end gap

STANDARD ITEM LIMIT

Piston rings end gap

"a": 120 mm (4.72 in.)

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1. Big-end side clearance: Check big-end of connecting rod for side clearance, with rod fitted and connected to its crank pin in the normal manner. If measured clearance is found to exceed its limit, replace connecting rod. Big-end side clearance STANDARD LIMIT REFERENCE Standard Limit 0.25 - 0.40 mm (0.0099 - 0.0150 in.) 0.45 mm (0.0177 in.)
2. Connecting rod alignment: Mount connecting rod on aligner to check it for bow and twist. If limit is exceeded, replace it. Limit on bow 0.05 mm (0.0020 in.) Limit on twist 0.10 mm (0.0039 in.)

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1. Inspect crank pin for uneven wear or damage. Measure crank pin for out-of-round or taper with a micrometer. If crank pin is damaged, or out-of round or taper is out of limit, replace crankshaft or regrind crank pin referring to the following step 6). Connecting rod bearing and crank pin STANDARD ITEM LIMIT Item Standard Crank pin diameter 49.982 - 50.000 mm (1.9768 - 1.9685 in.) Out-of-round "A"-"B" Taper "a"-"b" Out-of-round and taper limits 0.01 mm (0.0004 in.)
2. Connecting rod bearing general information: Inspect bearing shells for signs of fusion, pitting, burn or flaking and observe contact pattern. Bearing shells found in defective condition must be replaced. Two kinds of connecting rod bearings are available; standard size bearing and 0.25 mm (0.0098 in.) undersize bearing. For identification of undersize bearing, it is painted red (1) at the position as indicated in the figure, undersize bearing thickness is 1.605 - 1.615 mm (0.0632 - 0.0635 in.) at the center of it.
3. Connecting rod bearing clearance: Before checking bearing clearance, clean bearing and crank pin. Install bearing in connecting rod and bearing cap. Place a piece of gauging plastic (1) to full width of crank pin as contacted by bearing (parallel to crankshaft), avoiding oil hole. Install connecting rod bearing cap (1) as follows. Point arrow mark (2) on cap to crankshaft pulley side. Apply engine oil to connecting rod bolts (3). Tighten all connecting rod bolts to 15 N.m (1.5 kgf-m, 11.0 lb-ft). Retighten them by turning through 45°. Repeat step d ) once again. Tightening torque Connecting rod bolt a: 15 N.m (1.5 kgf-m, 11.0 lb-ft) 45° and 45° by the specified procedure NOTE: DO NOT turn crankshaft with gauging plastic installed. Remove connecting rod bearing cap, and using a scale (2) on gauging plastic envelope, measure gauging plastic (1) width at the widest point (clearance). If clearance exceeds its limit, select connecting rod bearing referring to «PISTONS, PISTON RINGS, CONNECTING RODS AND CYLINDERS INSPECTION AND CLEANING»(ref-251061-S19702484192007032000000) below mentioned item. After selecting new bearing, recheck clearance. Bearing clearance BEARING CLEARANCE REFERENCE Standard Limit 0.045 - 0.063 mm (0.0018 - 0.0025 in.) 0.08 mm (0.0031 in.) If clearance can not be brought to within its limit even by using a new standard size bearing, replace crankshaft or regrind crankpin to undersize as follows. Install 0.25 mm undersize bearing to connecting rod big end. Measure bore diameter of connecting rod big end. Regrind crankpin to the following finished diameter. Finished crankpin diameter = Measured big end bore diameter (including undersize bearing - 0.054 mm (0.0021 in.) Confirm that bearing clearance is within the standard value. NOTE: After checking the connecting rod bearing clearance, make sure that checking for "Connecting rod bolt deformation".
4. Selection of connecting rod bearings: NOTE: If bearing is in malcondition or bearing clearance is out of specification, select a new standard bearing according to the following procedure and install it. When replacing crankshaft or connecting rod and its bearing due to any reason, select new standard bearings to be installed referring to numbers stamped on connecting rod and its cap and/or alphabets stamped on crank web of No. 3 cylinder. Check stamped numbers on connecting rod and its cap as shown. Three kinds of numbers ("1", "2" and "3") represent the following connecting rod big end inside diameters. For example, stamped number "1" indicates that corresponding connecting rod big-end inside diameter is 53.0000 - 53.0060 mm (2.0867 - 2.0868 in.). Connecting rod big-end inside diameter CONNECTING ROD BIG-END INSIDE DIAMETER REFERENCE Stamped numbers Connecting rod big-end inside diameter 1 53.0000 - 53.0060 mm (2.0867 - 2.0868 in.) 2 53.0061 - 53.0120 mm (2.0869 - 2.0870 in.) 3 53.0121 - 53.0180 mm (2.0871 - 2.0873 in.) Next, check crank pin diameter. On crank web of No. 3 cylinder, four alphabets are stamped as shown in the figure. Three kinds of alphabet ("A", "B" and "C") represent the following crank pin diameter respectively. For example, stamped "A" indicates that corresponding crank pin diameter is 49.9940 - 50.0000 mm (1.9683 - 1.9685 in.). Crank pin diameter CRANK PIN DIAMETER REFERENCE Stamped alphabet Crank pin diameter (without bearing) A 49.9940 - 50.0000 mm (1.9683 - 1.9685 in.) B 49.9880 - 49.9939 mm (1.9681 - 1.9682 in.) C 49.9820 - 49.9879 mm (1.9677 - 1.9680 in.) There are 5 kinds of standard bearings differing in thickness. To distinguish them, they are painted in the following colors at the position as indicated in the figure. Each color indicated the following thickness at the center of bearing. Standard size of connecting rod bearing thickness STANDARD SIZE OF CONNECTING ROD BEARING THICKNESS REFERENCE Color painted Bearing thickness Blue 1.494 - 1.497 mm (0.05882 - 0.05893 in.) Yellow 1.491 - 1.494 mm (0.05871 - 0.05881 in.) Nothing 1.488 - 1.491 mm (0.05859 - 0.05870 in.) Black 1.485 - 1.488 mm (0.05847 - 0.05858 in.) Green 1.482 - 1.485 mm (0.05835 - 0.05846 in.) From number stamped on connecting rod and its cap and alphabet stamped on crank web No. 3 cylinder, determine new standard bearing to be installed to connecting rod big-end inside, by referring to the table. For example, if number stamped on connecting rod and its cap is "1" and alphabet stamped on crank web No. 3 cylinder is "B", install a new standard bearing painted in "Black" to its connecting rod big-end inside. Specifications of new standard connecting rod bearing size CONNECTING ROD BIG-END INSIDE DIAMETER REFERENCE Number stamped on connecting rod and its cap (Connecting rod big end inside diameter) 1 2 3 Alphabet stamped on crank web of No. 3 cylinder (Crank pin diameter) A Green Black Nothing B Black Nothing Yellow C Nothing Yellow Blue New standard bearing to be installed. Check bearing clearance with newly selected standard bearing referring to «CRANK PIN AND CONNECTING ROD BEARINGS»(ref-251061-S39319213682007032000000) . If clearance still exceeds its limit, use next thicker bearing and recheck clearance.
5. Connecting rod bolt deformation Measure each thread diameter of connecting rod bolts (1) at "A" on 28.5 mm (1.12 in.) from bolt mounting surface and "B" on 42.0 mm (1.65 in.) from bolt mounting surface by using a micrometer (2). Calculate difference in diameters ("A"-"B"). If it exceeds limit, replace connecting rod. Connecting rod bolt measurement points "a": 28.5 mm (1.12 in.) "b": 42.0 mm (1.65 in.) Connecting rod bolt diameter difference limit ("A"-"B"): 0.1 mm (0.004 in.)

Scheme 188

Clean carbon from piston head and ring grooves, using a suitable tool.

Scheme 189

Crankshaft runout

Using a dial gauge, measure runout at center journal. Rotate crankshaft slowly. If runout exceeds its limit, replace crankshaft.

Limit on runout

0.06 mm (0.0023 in.)

Scheme 190

Crankshaft thrust play

Measure this play with crankshaft set in cylinder block in the normal manner, that is, with thrust bearing and lower crankcase installed.

Tighten crankcase bolts referring to MAIN BEARINGS, CRANKSHAFT AND CYLINDER BLOCK REMOVAL AND INSTALLATION .

Use a dial gauge to read displacement in axial (thrust) direction of crankshaft.

If its limit is exceeded, replace thrust bearing with new standard one or oversize one to obtain standard thrust play.

Crankshaft Thrust Play

Standard: 0.10 - 0.35 mm (0.0039 - 0.0138 in.)

Limit: 0.42 mm (0.0149 in.)

Scheme 191

Thickness of crankshaft thrust bearing

CRANKSHAFT THRUST BEARING THICKNESS REFERENCE

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Out-of-round and taper (uneven wear) of journals

An unevenly worn crankshaft journal shows up as a difference in diameter at a cross section or along its length (or both). This difference, if any, is determined by taking micrometer readings. If any one of journals is badly damaged or if amount of uneven wear in the sense exceeds its limit, regrind or replace crankshaft.

Limit on out-of-round and taper

0.01 mm (0.0004 in.)

Out-of-round

"A"-"B"

Taper

"a"-"b"

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Main bearing clearance

Check clearance by using gauging plastic according to the following procedure.

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1. Remove lower crankcase.
2. Clean bearings and main journals.
3. Place a piece of gauging plastic (1) to full width of bearing (parallel to crankshaft) on journal, avoiding oil hole.
4. Install lower crankcase to cylinder block referring to «MAIN BEARINGS, CRANKSHAFT AND CYLINDER BLOCK REMOVAL AND INSTALLATION»(ref-251061-S33065166742007032000000) . NOTE: Do not rotate crankshaft while gauging plastic is installed.
5. Remove lower crankcase and using scale (2) on gauging plastic envelop (1), measure gauging plastic width at its widest point. If clearance exceeds its limit, replace bearing. Always replace both upper and lower inserts as a unit. A new standard bearing may produce proper clearance. If not, it will be necessary to regrind crankshaft journal for use of 0.25 mm undersize bearing. After selecting new bearing, recheck clearance. Main Bearing Clearance Standard: 0.032 - 0.050 mm (0.0013 - 0.0019 in.) Limit: 0.060 mm (0.0023 in.)

Selection of main bearings

STANDARD BEARING

If bearing is in malcondition, or bearing clearance is out of specification, select a new standard bearing according to the following procedure and install it.

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1. First check journal diameter. As shown in figure, crank web No.2 has stamped numbers. Three kinds of numbers ("1", "2" and "3") represent following journal diameters. Journal diameter JOURNAL DIAMETER REFERENCE Stamped numbers Journal diameter 1 58.0000 - 58.0060 mm (2.2835 - 2.2837 in.) 2 57.9940 - 57.9999 mm (2.2832 - 2.2834 in.) 3 57.9880 - 57.9939 mm (2.2830 - 2.2832 in.) Stamped numbers on crank web No.2 (3) represent journal diameters marked with an arrow in figure respectively. For example, stamped number "1" indicates that corresponding journal diameter is 58.0000 - 58.0060 mm (2.2835 - 2.2837 in.).
2. Next, check crankcase (bearing cap) bore diameter without bearing. On lower crankcase five alphabets are stamped as shown in figure. Three kinds of alphabets ("A", "B" and "C") represent the following cap bore diameters. Bore diameter for bearing cap CRANKCASE BORE DIAMETER REFERENCE Stamped alphabet A 61.9940 - 62.0000 mm (2.4407 - 2.4409 in.) B 62.0001 - 62.0060 mm (2.4410 - 2.4411 in.) C 62.0061 - 62.0120 mm (2.4412 - 2.4414 in.) Stamped alphabets on lower crankcase represent crankcase bore diameter marked with an arrow in figure respectively. For example, stamped alphabet "A" at bearing cap No.2 indicates that bearing cap bore diameter of bearing cap No.2 is 61.9940 - 62.0000 mm (2.4407 - 2.4409 in.).
3. There are 5 kinds of standard bearings differing in thickness. To distinguish them, they are painted (1) in the following colors at the position as indicated in figure. Each color indicates the following thickness at the center of bearing. Standard size main bearing thickness MAIN BEARING THICKNESS REFERENCE Color painted Bearing thickness Green 1.991 - 1.994 mm (0.0784 - 0.0785 in.) Black 1.994 - 1.997 mm (0.0785 - 0.0786 in.) Colorless (no paint) 1.997 - 2.000 mm (0.0786 - 0.0787 in.) Yellow 2.000 - 2.003 mm (0.0787 - 0.0788 in.) Blue 2.003 - 2.006 mm (0.0788 - 0.0789 in.)
4. From number stamped on crank web No. 2 and alphabets stamped on lower crankcase, determine new standard bearing to be installed to journal, by referring to table shown. For example, if number stamped on crank web No. 2 is "1" and alphabet stamped on lower crankcase is "B", install a new standard bearing painted in "Black" to its journal. New standard size bearing specification NEW STANDARD SIZE BEARING SPECIFICATION Number stamped on crank web (Journal diameter) 1 2 3 Alphabet stamped on lower crankcase (Cap bore diameter) A Green Black Colorless B Black Colorless Yellow C Colorless Yellow Blue
5. Using gauging plastic (1) and scale (2), check bearing clearance with newly selected standard bearing. If clearance still exceeds its limit, use next thicker bearing and recheck clearance.
6. When replacing crankshaft or cylinder block and lower crank case due to any reason, select new standard bearings to be installed by referring to number stamped on new crankshaft or alphabets stamped on new lower crankcase.

UNDERSIZE BEARING (0.25 mm)

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1. 0.25 mm undersize bearing is available, in five kinds varying in thickness. To distinguish them, each bearing is painted (1) in the following colors at such position as indicated in figure. Each color represents the following thickness at the center of bearing. Undersize main bearing thickness MAIN BEARING THICKNESS REFERENCE Color painted Bearing thickness Green & Red 2.116 - 2.119 mm (0.0833 - 0.0834 in.) Black & Red 2.119 - 2.122 mm (0.0834 - 0.0835 in.) Red only 2.122 - 2.125 mm (0.0835 - 0.0836 in.) Yellow & Red 2.125 - 2.128 mm (0.0836 - 0.0837 in.) Blue & Red 2.128 - 2.131 mm (0.0837 - 0.0838 in.)
2. If necessary, regrind crankshaft journal and select under-size bearing to use with it as follows. Regrind journal to the following finished diameter. Finished journal diameter 57.7380 - 57.7506 mm (2.2731 - 2.2738 in.) Measurement should be taken in two directions perpendicular to each other in order to check for out-of-round. Using micrometer, measure reground journal diameter. Using journal diameter measured and alphabets stamped on lower crankcase, select an undersize bearing by referring to the following table. Check bearing clearance with newly selected undersize bearing. Undersize bearing specification UNDERSIZE BEARING SPECIFICATION Measured journal diameter 57.7500 - 57.7506 mm (2.2737 - 2.2738 in.) 57.7440 - 57.7499 mm (2.2734 - 2.2736 in.) 57.7380 - 57.7439 mm (2.2731 - 2.2733 in.) Alphabets stamped on lower crankcase A Green & Red Black & Red Red only B Black & Red Red only Yellow & Red C Red only Yellow & Red Blue & Red

Crankshaft Position Sensor Plate

Check teeth of plate for damage.

If any damage is found, replace crankshaft (1).

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Oil Pump Sprocket

Check teeth of sprocket for wear or damage.

If any damage or wear is found, replace crankshaft (1).

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Oil Pump Chain

Check oil pump chain for wear or damage.

Flywheel

1. If ring gear is damaged, cracked or worn, replace flywheel.
2. If the surface contacting clutch disc is damaged, or excessively worn, replace flywheel.
3. Check flywheel face runout with a dial gauge.

If runout exceeds its limit, replace flywheel.

Limit on runout

0.2 mm (0.0078 in.)

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1. Distortion of gasketed surface
2. Using straightedge and thickness gauge, check gasketed surface for distortion and, if flatness exceeds its limit, correct It. Flatness Limit 0.06 mm (0.0024 in.)

Scheme 206

1. When any cylinder needs reboring, all other cylinders must also be rebored at the same time. Oversize piston specification OVERSIZE PISTON SPECIFICATION Size Piston diameter STD 89.970 - 89.990 mm (3.5422 - 3.5429 in.) O/S 0.50 90.470 - 90.490 mm (3.5619 - 3.5626 in.)
2. Using micrometer, measure piston diameter.
3. Calculate cylinder bore diameter to be rebored as follows. D = A + B - C D: Cylinder bore diameter to be rebored. A: Piston diameter as measured. B: Piston clearance = 0.02 - 0.04 mm (0.0008 - 0.0015 in.) C: Allowance for honing = 0.02 mm (0.0008 in.)
4. Rebore and hone cylinder to calculated dimension. NOTE: Before reboring, install lower crankcase and tighten to specification to avoid distortion of bearing bores.
5. Measure piston clearance after honing.

Check Valve

Check check valve for clogging and ball for being stuck.

Scheme 207

Recommended Service Material

RECOMMENDED SERVICE MATERIAL REFERENCE