Cylinder Head and Camshaft Reassembly

12. 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: 3.2 m-kg (23.1 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

NOTE:
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 it is in its holder down below.

e. Rotate the engine in a counterclockwise direction until the crankcase pointer and "T" mark on the timing plate are aligned.

f.   With the cylinders No. 1 and 4 at the top dead center, slip the cam chain over the sprocket,

g.   Lubricate all cam caps and cam bearings surfaces liberally with oil.

h. Place the cam caps in their proper positions. The caps are identified "1-1" through "I-3" for intake and "E-1" through "E-3" for exhaust. Install the bolts only finger tight.

CAUTION:
The cam caps must be tightened evenly or damage to the cylinder head, cam caps and cam will result. The spaces between the
caps and cylinder head should be equal.

I. Torque the cam cap bolts in two stages and final torque to the specification.

Tightening torque: 1.0 m-kg (7.2 ft-lb)

13. Cam chain, cam sprockets and chain tensioner
a. Rotate each cam shaft until the dot on the cam is aligned with the arrow on the center cam cap.

CAUTION:
Use extreme caution when rotating the cams. Two possible dangers exist. First, the wrench may contact the head and fracture it. Or second, a valve may become bent if the cam is turned the wrong way.

b). Carefully lift the cam chain from the exhaust cam sprocket and pull upward to remove any slack in the chain between the crankshaft and the exhaust cam sprocket. With all slack removed, place the chain back on the cam sprocket.

c). Grip each sprocket simultaneously and place them on the camshaft shoulders while continuing to keep tension on the chain from the crankshaft to the exhaust sprocket.

CAUTION:
Use only the special hardened shouldered bolts to install the cam chain sprockets to the cams.
Make sure the rollers of the cam chain are centered on both chain guides.

d.   Rotate the sprockets slightly to align the bolt holes and insert one special bolt in each sprocket.

NOTE:
Tighten only finger tight at this time.

e.   Install the center chain guide.

f. Rotate the crankshaft counterclockwise and align the "C" mark on the timing plate with the timing pointer.

 

This model has been equipped the automatic cam chain tensioner. No adjustment is necessary.

When installing this tensioner onto the cylinder proceed as follows:

1.    Remove the end plug and spring from the tensioner assembly.

2.    Unlock the oneway cam by pushing it with your finger and push the tensioner rod into the tensioner body until it stops.

3.    Install the tensioner to the cylinder and torque the bolts to the specification.

Tightening torque: 1.0 m-kg (7.2 ft-lb)

4. Reinstall the spring and end plug with the gasket. Torque the end plug to the specification.

Tightening torque: 1.5 m-kg (11 ft-lb)

k. Rotate the crankshaft more than one full revolution and align the "T" mark on the timing plate with the timing pointer. With the crankshaft at the "T" mark, the dots on the cams should be aligned with the raised arrows on the center cam caps. If they are not aligned, disassemble the sprockets and chain tensioner and repeat above procedures.

I. Rotate the crankshaft and install the two remaining shoulder bolts into the cam sprockets. Torque all four sprocket holding bolts to the specification.

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

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

m. Adjust all valves as described in the "PERIODIC INSPECTIONS AND ADJUSTMENTS".

n. Install the cylinder head cover with a new gasket.

o. Install the left and right crankcase covers. The left crankcase cover (pickup coil cover) is required a gasket.