650RJ (Seca)
Cylinder and Piston -- Inspection and Repair
F. Cylinder
1. Inspect the cylinder walls for scratches. If vertical scratches are evident, the cylinder wall should be rebored or the cylinder should be replaced.
2. Measure cylinder wall wear as shown. If wear is excessive, compression pressure will decrease. Rebore the cylinder wall and replace the piston and piston rings. Cylinder wear should be measured at three depths with a cylinder bore gauge. (See illustration.)
Engine Removal
ENGINE REMOVAL
NOTE:
It is not necessary to remove the engine in order to remove the cylinder head, cylinder, or pistons.
A . Preparation for Removal
1 All dirt, mud, dust and foreign material should be thoroughly removed from the exterior of the engine before removal and disassembly. This will help prevent any harmful foreign material from getting into the engine oil.
Clutch and Shifter Reassembly
5. Clutch assembly
a. Install the thrust plate onto the transmission main axle.
1. Thrust plate
b. Install the oil pump drive sprocket onto the main axle without the spacer collar and place the oil pump drive chain on its sprocket.
1. Oil pump drive sprocket
Cylinder Head Removal
ENGINE OVERHAUL
A. Cylinder Head and Cylinder
1. Remove the cylinder head cover.
2. Remove the left crankcase cover (pickup coil cover).
3. Remove the cam chain tensioner.
Lower Crankcase Reassembly
2. Lower crankcase
a. Install the shift cam and secure it with the guide pin. Install the stopper plate and bolt and tighten securely.
b. Install the neutral switch.
c. Install the transmission drive axle assembly into the crankcase.
Pistons and Cylinder Reassembly
11. Pistons and Cylinder a. Install the pistons on the rods. The arrow on the piston must point to the front of the engine.
NOTE:--------------------------------------------------------
Before installing the piston pin clips, cover
the crankcase with a clean rag so you will
not accidentally drop the circlip into the
crankcase.
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.
Generator, Starter and Pick-up Coil Reassembly
8. A.C. Generator
a. Install the rotor onto the shaft and
tighten the bolt using the rotor holding
tool (special tool) as shown.
1. Rotor holding tool
Tightening torque: 5.5 m-kg (39.8 ft-lb)