Yamaha EF1000 Service Manual

							ENGINE ENG 
JOB INSTRUCTION CHART 
Order Job name/Parts  name Oty Remarks 
Removal of Engine 
Remove the parts in order. 
Body cover/Fuel tank Refer to BODY COVER and 
FUEL TANK section. 
Muffler/Air filter Refer to MUFFLER and 
AIR FILTER section. 
1 Spark plug cap 1 
2 Oil  level  lead/Engine stop lead 1 
3 C.D.I. coupler 1 
4 Condenser lead 2 
5 DC rectifier coupler 1 
6 Main coil coupler 1 
7 Sub coil coupler 1 
8 Nut 4 
9 Earth lead 1 
10 Fuel tank breather hose 1 
11 Engine assembly 1 Reverse the removal procedure for 
installation. 
3-4  
						

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CYLINDER HEAD COVER, CYLINDER HEAD, VALVE ENG B 
CYLINDER HEAD COVER,  CYLINDER HEAD, VALVE 
2 
5 j11 Nm (1.1 m•kg, 8.0 ft•lb) I 
10 Nm (1.0 m•kg, 7.2 ft•lb) 
2 
3-5  
						

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CYLINDER HEAD COVER, CYLINDER HEAD, VALVE ENG [g 
JOB INSTRUCTION  CHART 
Order Job name/Parts name Qty Remarks 
Removal 
of cylinder  head cover, Remove the parts in order. 
cylinder  head and 
valve 
Recoil 
starter Refer to RECOIL  STARTER 
section in chapter 3. 
Air filter, Carburetor Refer to CARBURETOR 
section in chapter 3. 
1 Spark plug 1 
2 Bolt 4 
3 Cylinder head cover 1 
4 Gasket  1 
5 Air shround 1 
1 
6 Air shround 2  1 
7 Bolt 4 NOTE: Follow proper tightening 
sequence. 
8 Cylinder head  1 NOTE: Set the piston at compression 
top dead center before 
removal. 
9 Gasket  1 
10 Dowel pin 2 
11 Push rod 2 
Reverse 
the removal 
procedure for installation. 
Disassembly of Cylinder head Disassemble the parts  in the order. 
CD Locknut 2 
@ Adjuster 2 
@ Rocker arm 2 
@ Valve retainer 2 
® Valve spring 2 
® Push rod guide 1 
(j) Exhaust valve 1 
® Intake valve 1 
Reverse 
the disasembly procedure 
for assembly. 
3-6  
						

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CYLINDER HEAD COVER, CYLINDER HEAD, VALVE ENG 8 
Intake Valve face: Exhaust Valve face: 
@ 
3-7 
CYLINDER HEAD INSPECTION 
1. Remove: 
•Carbon deposits 
Use rounded scraper. 
2. Measure: 
•Cylinder head warpage 
Exceeds allowable limit ---?Resurface. 
I~ 
Warpage Limit: 
0.1 mm (0.004 in) 
VALVE 
REMOVAL 
1. Remove: 
•Valve spring retainer CD 
•Vale spring ~ 
•Valve ® 
VALVE INSPECTION 
1. Inspect: 
•Valve length@ 
•Valve face diameter@ 
Valve length: 
Intake: 53.4 mm (2.10  in) 
Exhaust: 53.6 mm (2.11  in) 
Valve face diameter: 
Intake: 19.0 mm (0.75 in) 
Exhaust: 17.0 mm (0.67 in)  
						

							CYLINDER HEAD COVER, CYLINDER HEAD,  VALVE ENG 
302-011 
3-8 
2. Inspect: 
•Valve stem diameter® 
Out of specification~Replace. 
Valve stem diameter: 
Standard: 
Intake: 5.0 mm (0.2 in) 
Exhaust: 5.0 mm (0.2 in) 
Limit: 
Intake: 4.89 mm (0.193 in) 
Exhaust: 4.87 mm (0.192 in) 
3. Measure: 
•Valve stem bend 
~ Valve stem bend limit: 
v A 0.01 mm (0.0004 in) 
Out of specification~Replace. 
VALVE SEAT INSPECTION 
1 .Measure: 
•Valve contact width ® 
Poor seating ~Looping. 
Out of specification~Replace. 
Valve contact width: 
Standard: 0.7 mm (0.03 in) 
Limit: 1.2 mm (0.047 in) 
2. Measure: 
•Valve seat contact width® 
Poor seating ~Looping. 
Out of specification~Replace. 
Valve seat contact width: 
Standard: 0.7 mm (0.03 in) 
Limit: 1.2 mm (0.047 in) 
Valve/Valve Seat Assembly Lapping 
1. Apply: 
•Coarse lapping  compound (Small amount to 
valve face) 
2.  Position: 
•Valve 
(in cylinder head)  
						

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CYLINDER HEAD COVER, CYLINDER HEAD, VALVE ENG 8 
302-017 
302-005 
3-9 
3. Rotate: 
•Valve 
Turn  until valve  and valve  seat are evenly 
polished,  then clean 
off compound. 
4. Repeat  above steps with fine compound and 
continue  lapping 
until valve face shows  a 
completely 
smooth surface uniformly. 
5. Eliminate: 
•Compound 
(from  valve face) 
6. 
Apply: 
•Mechanics bluing  dye (Dykem) CD 
(to valve  face and seat) 
7.  Rotate: 
•Valve 
Valve must make full seat contact indicat­
ed 
by grey  surface all around  valve face 
where  bluing 
was removed. 
8. 
Apply: 
•Solvent 
(into  each  intake  and exhaust  port) 
Leakage  past valve 
seat-+ Repeat  valve lap­
ping  until seal is complete. 
NOTE: --------------------------
Pour solvent into intake  and exhaust  ports only 
after 
completion of all valve work and  assembly 
of head  parts. 
Valve  Spring Measurement 
1 . Measure: 
• Valve  spring  free length CD 
Out of specification--+ Replace. 
Valve spring  free length: 
27.4 mm (1.08 in) 
Limit: 
24.4 mm (0.96 in)  
						

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CYLINDER HEAD COVER, CYLINDER HEAD,  VALVE ENG 8 
-~-® 
2 
4 
3-10 
2. Measure: 
•Valve spring tilt@ 
Use a square 
Out of specification~Replace. 
I~ 
lilt limit: 
0.8 mm (0.031 in) 
PUSH  ROD INSPECTION 
1. Measure: 
•Push rod bend 
Roll on V-block 
Exceeds bending limit~Replace. 
I~ 
Bend Limit: 
0.5 mm (0.02 in) 
CYLINDER HEAD INSTALLATION 
1. Install: 
•Cylinder head assembly 
NOTE: ________________________ ___ 
Follow proper tightening sequence. 
  Cylinder head bolt: 
~~ 11 Nm (1.1 m•kg, 8.0 ft•lb) 
2. Adjust: 
•Valve clearance 
Refer to VALVE CLEARANCE ADJUST­
MENT section  in CHAPTER 2.  
						

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PISTON, CAMSHAFT, CRANKCASE, CRANKSHAFT ENG -
PISTON, CAMSHAFT, CRANKCASE,  CRANKSHAFT 
l 
m 
/ 
3-11 
l 
m 
2  
						

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PISTON, CAMSHAFT, CRANKCASE,  CRANKSHAFT ENG 8 
JOB INSTRUCTION CHART 
Order Job name/Parts name Oty Remarks 
Removal of Piston,  Camshaft 
Remove the parts in order. 
Crankcase  and Crankshaft 
Generator,  Rotor 
Refer 
to the GENERATOR section. 
Engine Refer to the ENGINE section 
Flywheel Refer to the FLYWHEEL section. 
1 Bolt 7 NOTE: Follow proper tightening 
sequence. 
2 
Crankcase cover 1 
3  Gasket 1 
4 
Dowel pin 2 
5 Camshaft 1 NOTE: Be sure to align the camshaft 
gear mark with crankshaft 
gear mark. 
6 
Valve lifter 2 
7 Bolt 2 
8 Connecting rod  cap 
1 NOTE: Be sure the connecting rod 
mark is aligned with the cap 
mark. 
9 Connecting rod 
10 Piston pin circlip 2 
11 Piston pin  1 
12 Piston 1 NOTE: Be sure the  V   mark on the 
piston head  faces to push 
rod side. 
13  Piston 
ring 
3 
NOTE: Be sure to install rings so 
that manufacturers marks 
faces to piston head. 
Be sure each piston ring end 
is positioned as illustration. 
14 Crankshaft 1 
15 Bolt 2 
16 
Oil  level gauge 
1 
Reverse 
the removal procedure 
for installation. 
3-12  
						

							PISTON, CAMSHAFT, CRANKCASE,  CRANKSHAFT ENG 
3-13 
CRANKSHAFT  REMOVAL 
1. Remove: 
•Camshaft 
NOTE: ________________________ _ 
Remove the camshaft, facing the camshaft 
gear mark to the crankshaft gear mark. 
2. Remove: 
•Valve lifter 
CAUTION: 
Mark the valve lifters so that the exhaust 
and intake valve sides are not confused. 
CAMSHAFT AND VALVE LIFTER  INSPECTION 
1. Measure: 
•Cam lobes length® 
Use a micrometer. 
Out of specification---+Replace. 
Cam lobe length @: 
Standard: 20.5 mm (0.81 in) 
Limit: 20.25 mm (0.80 in)