Cylinder Head and Camshaft Reassembly

Submitted by xjcdadmin on Fri, 09/21/2018 - 20:30

Cylinder head and Cam shafts

a. Install the new cylinder head gasket. Install the dowel pins and "O-rings". Locate the cam chain cavity cylinder seal with the tabs down.

b.   Install the cylinder head onto the cylinder. Pull the cam chain through the cylinder head as it is installed. Tie the cam chain so that it does not fall into the crankcase.

c.   Place the upper cylinder head nuts and washers in place. Follow the illustration for the proper tightening sequence. Torque all nuts in two stages and final torque the upper nuts to the specification.

Tightening torque: 3.5 m-kg (25 ft-lb)

Don't forget the lower nuts on the front and rear of the cylinder head. Torque to the specification.

Tightening torque: 2.0 m-kg (14.5 ft-lb)

a. Copper washers


Tighten the nuts in two stages, 1/2 torque value and then full torque value. Also lubricate the bolt threads with the engine oil to achieve proper torque values.

d. Install the front cam chain guide being certain that the lower end is resting in the cam chain guide slot in the crankcase down below.



Cam chain sprockets installing steps:


• Align the "T" mark on the timing plate (1) with the stationary pointer on the pickup coil (2). Do not turn the crankshaft when installing the sprockets.

•   Place the cam chain onto the exhaust sprocket (3).


•   Install the sprockets and finger tighten the sprocket bolts.


•   Rotate the exhaust camshaft to align the punched mark on the camshaft (4) with the arrow on the center cam cap (5).

•   Force the exhaust camshaft clockwise to remove the cam chain slack.


•   Place the cam chain onto the intake sprocket.


•   Install the sprocket and finger tighten the sprocket bolt.


•   Rotate the intake camshaft to align the punched mark on the camshaft with the arrow on the center cam cap.


•   Force the intake camshaft clockwise to remove all the cam chain slack.

•   Insert your finger into the cam chain tensioner hole, and push the cam chain guide inward (6)


•  While pushing the cam chain guide, be sure camshaft timing marks align with the cap holes.


•   Remove the intake sprocket if marks do not align.


•   Change the meshing position of sprocket and cam chain.


•   Install the center cam chain guide.

Cam chain tensioner installation steps:


•   Remove the tensioner end cap bolt and spring.


•   Release the cam chain tensioner one-way cam (1) and push the tensioner rod into the tensioner body.

• Install the tensioner with a new gasket onto the cylinder.


Torque to 1.2 m-kg (8.4 ft-lb)


• Install the tensioner springs and end cap bolt (1). Tighten the bolt to 0.9 m-kg (6.5 ft-lb)

•  Turn the crankshaft and install the sprocket securing bolts.


•  Tighten the sprocket bolts to 2.0 m-kg (14 ft-lb)


Be sure to attain the specified torque value to avoid the possibility of these bolts coming loose and causing damage to the engine.

3.     Apply engine oil to the cam chain, sprockets, camshafts, and valves.


4.     Turn the crankshaft counterclockwise a few turns to ensure that it turns smoothly.


Be sure the exhaust and intake camshaft marks are aligned with the cam cap marks.


5. Measure:


• Valve clearance


Adjust to specification as described in under Valve Clearance Adjustments:


IN: 0.11 ~ 0.15mm (0.0043 ~ 0.0059 in)


EX: 0.16-0.20 mm (0.0063 ~ 0.0079 in)

6. Install:


Cylinder Head Cover: 1.0 m-kg (7.2ft-lb) 


Spark Plug: 20 Nm (2.0 nvkg, 14 ft-lb)

7. Install:


•   Gasket


Crankshaft End Cover (Left): 0.7 m-kg, 5.1 ft-lb)