Yamaha EF1000 Service Manual

							STARTER WIRE ADJUSTMENT ~~~~j I C!it I 
STARTER WIRE ADJUSTMENT 
2-6 
1. Remove: 
•Rear cover 
•Side cover 1 
Adjustment  steps: 
a. Set the control lever to ON. 
b. Loosen the lock nut CD and nut@. 
c. Turn the nut @ clockwise ® until the 
open side of the lever ® becomes free 
from the stopper@. 
d. Loosen the nut @ 1/2 turn counterclock­
wise and secure the locknut G). 
e. Set the control lever to the 1-..1 position. 
f. Check whether the closed side of the 
lever@ contacts the stopper@. 
Contacts the stopper--7Correct. 
There  is a gap between the lever @ and 
stopper@ --7* 
*Loosen the nut@ another 1/2 turn 
counterclockwise and secure the lock 
nut G). 
g. Return to step T. 
2. Install: 
•Side cover 1 
•Rear cover 
FUEL LINE 
1. Inspect: 
•  Fuel 
hose 
Clacks/Damage--7Replace 
Poor connection--7Correct  
						

							.// 
+ I I 1 
710-035 741-035 
r~g~l ~ 1 AIR FILTER/MUFFLER  _  _ ~ _ 
2-7 
AIR FILTER 
1. Remove: 
•Rear cover 
•Air filter cover CD 
•Air filter element~ 
2. Inspect: 
•Element 
Clogging~Wash the element in solvent and 
dry. 
Oil the element and  squeeze out excess oil. 
Damage~ Replace. 
Recommended Oil: 
3. Install: 
Foam-air-filter oil 
or 
SAE # 20 motor oil 
• Air filter  element 
• 
Air filter cover 
NOTE: --------------------------
Do not wring out the element. This could cause 
it to tear. 
The engine should never run without the ele­
ment; excessive piston and/or cylinder wear 
may result. 
4. Install: 
•Rear cover 
MUFFLER 
1. Remove: 
•Rear cover 
•Muffler  
						

							I
IANDSJP I ~~ I VALVE CLEARANCE ADJUSTMENT ~ 
-------------------------------------------------
2-8 
2. Decarbonize: 
1) Tap on the muffler in the area shown in 
the illustration. 
CAUTION: 
Dont use a wire to clean or the noise damp­
ing material may come out, reducing the 
damping effect. 
2) Shake out the loose carbon from car­
bon 
outlet CD of muffler. 
VALVE CLEARANCE ADJUSTMENT 
1. Remove: 
•Body panel 
•Air shroud 
•Gasket 
•Cylinder head cover 
•Spark plug 
2.  Measure: 
•Valve clearance 
Out of specification---> Adjust. 
Intake Valve 
(Cold) 
0.1 mm 
(0.004 in) 
Exhaust Valve 
(Cold) 
0.1 mm 
(0.004 in) 
NOTE: -------------------------
•Be sure  piston is at Top  Dead  Center  (TDC) on 
compression  stroke when measuring  clearance. 
•Valve clearance must be measured  when the en­
gine 
is cool to the  touch.  
						

							I
IANDSJP 1 ~o• 1 COMPRESSION PRESSURE MEASUREMENT _ ~ 
-------------------------------------------------
2-9 
Valve clearance adjustment 
1. Turn the crankshaft until the piston reach­
es 
top dead center (T.D.C.). 
2. Loosen the locknut CD and insert the 0.1 
mm (0.004 in) Thickness Gauge YU-
26900-9  (90890-03079) between rocker 
arm and valve stem. 
3. Turn the adjuster @ in or out to obtain 
the proper Thickness Gauge resistance 
by pushing and pulling it. 
Adjuster Resistance Valve Clearance 
Turn in Increase Decrease 
Turn out Decrease Increase 
4. Tighten the locknut G). 
Adjuster Locknut: 
10 Nm (1.0 m•kg, 7.2 ft•lb) 
COMPRESSION PRESSURE 
MEASUREMENT 
Insufficient compression  pressure will result in 
performance 
loss and  may  indicate leaking  valves 
or worn or damaged  piston rings. 
1. Measure: 
•Valve clearance 
2. Warm up engine for several minutes,  then 
stop 
the engine. 
3. Remove: 
•Spark plugs 
4. Connect: 
•Compression Gauge YU-33223 (90890-
03081 
l CD 
•Adapter YU-33223-3 (90890-04082)@ 
5. Measure: 
•Compression 
Standard compression pressure: 
100 kPa  {1.0 kg/cm2
, 14.2  psi) 
A WARNING 
When cranking engine, ground spark plug 
wires to prevent sparking.  
						

							CYLINDER HEAD/ 
BREATHER HOSE INSPECTION 
2-10 
Compression test steps (below minimum 
levels): 
•Squirt a few drops of oil into cylinder. 
•Measure compression  again 
Reading 
Diagnosis 
Higher than without •Worn cylinder, 
oil piston and piston 
rings 
Same as without oil •Defective piston, 
ring(s),  valve(s) and 
cylinder head gasket 
•Improper valve 
timing and valve 
clearance 
Compression test steps (above maximum 
levels): 
•  Check  cylinder head, valve surfaces,  or piston 
crown for carbon  deposits. 
CYLINDER HEAD 
1. Remove: 
•Carbon deposits 
Refer to the CYLINDER HEAD INSPEC­
TION section in CHAPTER 3. 
BREATHER HOSE INSPECTION 
1. Inspect: 
•Crankcase breather hose CD 
Cracks/Damage-?Replace. 
Loose connection---+Correct.  
						

							ENGINE SPEED ADJUSTMENT I 
GOVERNOR ADJUSTMENT 
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2-11 
ENGINE SPEED ADJUSTMENT 
1. Adjust: 
•Engine speed (with no load) 
Engine speed adjustment  steps: 
1. Install the Tachometer (YU-8036-A). 
2. Start the engine and warm up for a few 
minutes. 
3. Adjust the engine speed by turning the 
adjust screw CD in or out. 
{:} Engine speed (with no load): 
3,700-3,800 rpm 
GOVERNOR  ADJUSTMENT 
1. Remove: 
•Body panel 
•Fuel tank 
2. Adjust: 
•Governor 
Governor adjustment  steps: 
1. Loosen the nut G). 
2. Turn the governor arm@ counterclock­
wise until it stops. 
3. Turn the governor shaft counterclock­
wise until it stops. 
4. Tighten the nut G).  
						

							____________ sP_A_R_K_P_Lu_G_I~IQI 
 , ,,~.._....._ __ 
2-12 
SPARK PLUG 
1. Remove: 
•Spark plug 
2. Inspect: 
•  Electrode 
CD 
Wear I Damage~ Replace. 
•Insulator  color 
~ 
3. Measure: 
•Plug gap@ 
Out of specification~ Regap. 
Use  a Wire  Gauge  or 
Feeler Gauge. 
Spark Plug Gap: 
0.6-0.7 mm (0.024-0.028 in) 
Clean the plug with a spark plug  cleaner if 
necessary. 
Standard  Spark Plug: 
BPR6HS 
(NGK) 
Before installing a  spark plug,  clean the gasket 
surface  and 
plug surface. 
4. Tighten: 
•Spark plug 
Spark Plug: 
20 Nm (2.0 m•kg, 14.5 ft-lb) 
NOTE=------------------
Finger-tighten CD the spark plug before  torqu­
ing 
(2) to specification.  
						

							•llllull 
AIR FITER, CARBURATOR, MUFFLER ENG 8 
ENGINE 
AIR FILTER, CARBURATOR,  MUFFLER 
151.111 
3-1  
						

							•I Ill nil 
AIR FITER, CARBURATOR,  MUFFLER ENG B 
JOB INSTRUCTION  CHART 
Order Job name/Parts name Oty Remarks 
Removal of Air filter, Carburator Remove the parts in order. 
and 
Muffler 
Body cover Refer to BODY COVER section 
in 
CHAPTER 2. 
Fuel tank Refer to FUEL TANK section 
in 
CHAPTER 2. 
1 Crankcase breather hose  1 
2 
Screw 2 
3 
Bolt 1 
4 
Air filter assmbly 1 
5 Air filter gasket 1 
6 Governor link rod  1 
7 
Carburetor assembly 1 
8 Carburetor cover 1 
9 Joint 1 
10 Intake manifold gasket  1 
11 Bolt 6 
12 Muffler cover 2  1 
13 Nut/Bolt 2/1 
14 Muffler assembly 1 
15 Muffler gasket  1 
16 Bolt 2 
17 Muffler cover 1 1 
Reverse 
the removal procedure 
for installation. 
3-2  
						

							ENGINE 
3-3 
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