Suzuki: Engine K6A-YH6. Manual — part 9

THEORY OF OPERATION

4-13

4

4.7 Cylinder Block and Lower
Crankcase

See Figure 4-14.

Figure 4-14

The cylinder block (1) is made of a lightweight aluminum
alloy. The cylinders contain press-fit, semi-wet style liners
for improved cooling and reliability.

The lower crankcase (2) is made of lightweight aluminum
alloy. The journal bearing caps are integrated into the
casting, which makes it possible to reduce weight,
improve rigidity, and suppress vibrating noise.

Crankshaft

See Figure 4-15.

Figure 4-15

The crankshaft (1) is constructed of cast iron. The
crankshaft has four main bearing journals and three rod
bearing journals, and is counterbalanced on rod throws 1
and 3 to reduce vibration. Each main journal contains a
two-piece main bearing (4 and 5), which is lubricated via
an oil hole (3). The third main journal contains a thrust
bearing (2). The front-mounted timing sprocket drives
both the timing chain and oil pump inner rotor. The
crankshaft pulley is equipped with a damper to reduce
vibration.

TN0496

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2

TN0497, 0498

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4

5

1

2

4-14

THEORY OF OPERATION

4

Connecting Rod

See Figure 4-16.

Figure 4-16

The connecting rod is made of carbon steel with an
H-shaped cross section. The rod consists of two pieces,
the main beam (1) and the rod cap (3), which is fastened
with special reamer type rod bolts and nuts. The small
end of the rod is machined for a full-floating piston pin. An
oil jet (2) lubricates the cylinder wall, piston, and piston
pin. The rod bearings (4) are made of an aluminum alloy.

Piston, Piston Rings, and Piston Pin

See Figures 4-17 and 4-18.

Figure 4-17

Figure 4-18

The three-ring, skirt-type, full-floating pistons (1) are
made of an aluminum alloy. The pistons are equipped
with intake valve reliefs (2) machined into the face. The
piston pin bores are equipped with “Ricardo Grooves” (3)
to aid in lubrication. The piston is assembled in the
engine with the floating-fit piston pin for lower friction.

All piston rings are located above the piston pin. The two
top rings are compression rings and the 3rd (6) is an oil
ring.

The 1st ring (4) is of barrel face type designed for
improved initial breaking in. The 2nd ring (5) is of taper
undercut type designed for better oil scraping
performance. A hard chrome is plated on the
circumference of the 1st ring for extended durability.

TN0499

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3

4

TN0527

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3

TN0529

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4

6

5-2

TESTS AND ADJUSTMENTS

5

5.1 Air Intake and Exhaust
Systems

Intake Manifold Vacuum Test

See Figure 5-1.

1.

Warm up the engine.

Figure 5-1

2.

Stop the engine.

3.

Remove hose (2) from PCV valve and install vacuum
gauge (1) to PCV hose (2).

NOTES

Cap or plug PCV valve.

Place transmission in neutral position.

4.

Start the engine. Measure the intake manifold
vacuum at idle.

Intake Manifold Vacuum at Idle: At least 7.7 psi (53
kPa)

5.

Stop the engine. Remove the vacuum gauge and
install the PCV hose.

PCV Valve/Hose Test

See Figures 5-2 and 5-3.

Figure 5-2

1.

Remove the PCV valve (1) from the cylinder head
cover.

2.

Start engine and bring to idle. Block the end opening
of PCV valve. Suction (vacuum) should be detected.

3.

If any abnormal condition is found, replace the PCV
valve and hose.

Figure 5-3

4.

Remove the PCV valve and verify the internal check
ball can be heard when shaking the valve.

5.

If any abnormal condition or restriction is found,
replace the PCV valve and hose.

Required Tools

Vacuum Gauge: Suzuki PN 09915-67311 or
Equivalent

TN0538

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TN0598

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TN0599

TESTS AND ADJUSTMENTS

5-3

5

5.2 Cooling System

Thermostat Test

See Figures 5-4 and 5-5.

Figure 5-4

1.

Check that the air bleed valve (1) of thermostat is not
blocked.

2.

Inspect valve seat (2) for any substance that could
interfere with sealing.

Figure 5-5

3.

Immerse the thermostat (4) in water and heat it
gradually with an appropriate heater (5).

4.

Observe thermometer (3) to verify that the
thermostat opens at the specified temperature.
Replace thermostat if not to specifications.

Thermostat Start-to-Open Temperature:
190°F (88°C)

Full Open Temperature: 205°F (96°C)

5.3 Cylinder Head, Cams, and
Valve Train

Valve Clearance Check and
Adjustment

See Figures 5-6 through 5-13.

Check

Figure 5-6

1.

Remove the cam cover (1). (See “Cam Cover” on
page 7-17.)

Figure 5-7

2.

Turn the crankshaft clockwise as viewed from front.

TN0429

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TN0430

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Valve

Clearance

Intake

Exhaust

Cold

0.007—0.009 in.
(0.18—0.23 mm)

0.012—0.014 in.
(0.30—0.35 mm)

TN0539

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TN0540