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INSP

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INTRODUCTION/MAINTENANCE INTERVALS CHART/

PERIODIC MAINTENANCE/LUBRICATION INTERVALS

PERIODIC INSPECTIONS AND ADJUSTMENTS

INTRODUCTION

This chapter includes all information necessary to perform recommended inspections and adjust-
ments. These preventive maintenance procedures, if followed, will ensure more reliable machine
operation and a longer service life. The need for costly overhaul work will be greatly reduced. This
information applies to machines already in service as well as new machines that are being prepared
for sale. All service technicians should be familiar with this entire chapter.

MAINTENANCE INTERVALS CHART

Proper periodic maintenance is important. Especially important are the maintenance services
related to emissions control. These controls not only function to ensure cleaner air but are also vital
to proper engine operation and maximum performance. In the following maintenance tables, the
services related to emissions control are indicated as “*” in the chart.

PERIODIC MAINTENANCE/LUBRICATION INTERVALS

*: Related to emission control system.

Item

Remarks

Pre-Opera-

tion check 

(daily)

Initial

Every

1 month or 

20 Hr

3 months 

or 50 Hr

6 months 
or 100 Hr

12 months 

or 300 Hr

*Spark plug

Check condition, adjust gap and clean.
Replace if necessary.

*Valve clearance

Check and adjust when engine is cold.

*Crankcase breather 
system

Check breather hose for cracks or damage.
Replace if necessary.

*Idle speed

Check and adjust engine idle speed.

*Exhaust system

Check for leakage.
Retighten or replace gasket if necessary.

Check muffler screen and spark arrester. 
Clean/replace if necessary.

Engine oil

Check oil level.

Replace.

*Air filter

Clean. Replace if necessary.

Fuel filter

Clean fuel cock and fuel tank filter.
Replace if necessary.

Fuel line

Check fuel hose for cracks or damage.
Replace if necessary.

*Choke knob

Check choke operation.

Cooling system

Check for fan damage.

Starting system

Check recoil starter operation.

*Decarbonization

More frequently if necessary.

Fittings/fasteners

Check all fittings and fasteners. 
Correct if necessary.

Summary of Contents for EF2800i - Inverter Generator

Page 1: ...SERVICE MANUAL EF2800i LIT 19616 00 92 7VU 28197 10 310115 ...

Page 2: ......

Page 3: ...l means ATTENTION BECOME ALERT YOUR SAFETY IS INVOLVED Failure to follow WARNING instructions could result in severe injury or death to the machine operator a bystander or a person inspecting or repairing the machine A CAUTION indicates special precautions that must be taken to avoid damage to the machine NOTE A NOTE provides key information to make pro cedures easier or clearer MANUAL FORMAT The ...

Page 4: ...bricant 8 Special tool 9 Tightening 0 Wear limit clearance A Engine speed B Ω V A Illustrated symbols C through K in the exploded diagram indicate the grades of lubri cant and the locations of the lubrication points C Apply engine oil D Apply gear oil E Apply molybdenum disulfide oil F Apply wheel bearing grease G Apply lightweight lithium soap base grease H Apply molybdenum disulfide grease I App...

Page 5: ...INDEX GENERAL INFORMATION GEN INFO 1 PERIODIC INSPECTIONS AND ADJUSTMENTS INSP ADJ 2 ENGINE ENG 3 ELECTRICAL ELEC 4 SPECIFICATIONS SPEC 5 ...

Page 6: ... 2 8 COMPRESSION PRESSURE 2 10 RATED ENGINE SPEED 2 11 BREATHER HOSE 2 11 ELECTRICAL 2 12 SPARK PLUG 2 12 ENGINE SWITCH 2 13 ECONOMY SWITCH 2 13 PILOT LIGHT 2 13 RECEPTACLE 2 14 DC CIRCUIT BREAKER 2 14 CHAPTER 3 ENGINE CONTROL PANEL 3 1 CONTROL BOX COVER AND FUEL TANK 3 3 MUFFLER AND AIR CLEANER 3 4 BREATHER HOSE INSTALLATION 3 5 MUFFLER ASSEMBLY 3 5 CONTROL UNIT AND AC CDI UNIT 3 6 ENGINE 3 7 CYL...

Page 7: ... PISTON ASSEMBLY 3 36 CRANKSHAFT ASSEMBLY 3 37 CARBURETOR 3 38 FLOAT HEIGHT INSPECTION 3 40 CHOKE CABLE INSTALLATION 3 41 THROTTLE CONTROL MOTOR 3 41 TROUBLESHOOTING 3 42 THROTTLE CONTROL SYSTEM 3 48 CHAPTER 4 ELECTRICAL ELECTRICAL COMPONENTS 4 1 CIRCUIT DIAGRAM 4 2 SWITCHES 4 3 CHECKING SWITCH CONTINUITY 4 3 IGNITION SYSTEM 4 4 TROUBLESHOOTING CHART 4 4 GENERATOR SYSTEM 4 9 TROUBLESHOOTING CHART ...

Page 8: ......

Page 9: ...s printed on a label 1 which is affixed to the generator as shown NOTE The first three characters of this number are for model identification the remaining digits are the unit production number SVU1010 SVU1020 STARTING SERIAL NUMBER 7VU 200101 NOTE Designs and specifications are subject to change without notice 1 ...

Page 10: ...place the gaskets O rings cotter pins and circlips with new parts when servicing engine SVU1060 4 Tightening torque Be sure to follow torque specifications When tightening bolts nuts or screws start with the largest diameter fastener and work from an inner position to an outer position in a crisscross pattern SVU1070 5 Notes on disassembly and assembly a Parts should be cleaned in solvent and blow...

Page 11: ...l all mating parts and bearings during reassembly Apply grease to the oil seal lips BEARINGS AND OIL SEALS Install the bearing s 1 and oil seal s 2 with their manufacture s marks or numbers facing outward In other words the stamped let ters must be on the side exposed to view When installing oil seal s apply a light coating of light weight lithium base grease to the seal lip s Oil the bearings lib...

Page 12: ...o remove the valve springs SVU1140 3 Thickness gauge P N YU 26900 9 90890 03079 This gauge is used to adjust valve clearance piston clearance and piston ring end gap SVU1150 4 Cylinder gauge Commercially obtainable This instrument is used for checking cylinder bore size and con dition SVU1160 5 Inductive tachometer P N YU 8036 A Engine tachometer P N 90890 03113 This instrument is used for reading...

Page 13: ... flywheel SVU1205 10 Rotor puller 1 P N YU 33270 2 P N 90890 01362 This tool is necessary for removing the flywheel SVU1210 1 SVU1220 2 11 Pocket tester P N YU 03112 90890 03112 This instrument is necessary for checking the electrical system SVU1230 12 Dynamic spark tester 1 P N YM 34487 Ignition checker 2 P N 90890 06754 This instrument is necessary for checking the ignition system components SVU...

Page 14: ...the services related to emissions control are indicated as in the chart PERIODIC MAINTENANCE LUBRICATION INTERVALS Related to emission control system Item Remarks Pre Opera tion check daily Initial Every 1 month or 20 Hr 3 months or 50 Hr 6 months or 100 Hr 12 months or 300 Hr Spark plug Check condition adjust gap and clean Replace if necessary Valve clearance Check and adjust when engine is cold ...

Page 15: ...ng light flashes Add oil Oil warning light does not flash OK ECON SW AC OVER LOAD BATTERY CHARGE ONLY 12V10A RESET 20A OFF DC PROTECTOR DC 1 SVU2020 2 Remove Oil filler cap 1 3 Check Check that the engine oil is at the spec ified level a Oil level checking steps Place the engine on a level surface Warm up the engine for several minutes Stop the engine Check that the engine oil is at the specified ...

Page 16: ...etely 6 Tighten Oil drain bolt 1 T R Oil drain bolt 17 Nm 1 7 m kg 12 ft lb SVU2040 7 Remove Oil filler cap 1 8 Fill NOTE Recommended engine oil classification API Service SE or SF if not available SD Recommended oil È YAMALUBE 4 10W 30 or SAE 10W 30 type SE É SAE 30 Ê SAE 20 Ë SAE 10W Engine oil quantity 0 6 L 0 53 Imp qt 0 63 US qt SVU2050 SVU2060 9 Install Oil filler cap OIL REPLACEMENT ...

Page 17: ...d then remove the debris from inside the cup 2 Remove Fuel cock cup 1 Gasket 2 Strainer 3 3 Inspect Fuel cock cup Dirt debris Clean Gasket 2 Damage Replace Strainer 3 Dirt debris Clean NOTE Clean the cup with solvent and then dry it thoroughly SVU2080 4 Install Strainer Gasket Fuel cock cup CAUTION Securely install the strainer cup to prevent fuel leaks T R Fuel cock cup 1 3 Nm 0 13 m kg 0 94 ft l...

Page 18: ...ng or in the vicinity of fuel 1 Remove Fuel tank cap 1 Fuel tank filter 2 2 Inspect Fuel tank filter Damage Replace 3 Clean Fuel tank filter NOTE Clean the fuel tank filter with solvent and then dry it thoroughly 4 Install Fuel tank filter Fuel tank cap WARNING Be sure the tank cap is tightened securely SVU2090 FUEL TANK FILTER ...

Page 19: ...y it thoroughly Oil the element and squeeze out the excess oil CAUTION Do not wring out the element this could cause it to tear Do not wash the element in gasoline or in acidic alkalinic or organic solvents SVU2120 4 Install Air filter element Air filter case cover Screws CAUTION The engine should never run without the element otherwise excessive piston and or cylinder wear may result AIR FILTER E...

Page 20: ... shown in the illustration to loosen carbon buildup and then shake it out of the end of the muffler CAUTION Don t use a wire to clean otherwise the noise damping material may come out and the damping effect may be reduced 3 Decarbonize Muffler screen Spark arrester 4 Install Spark arrester Muffler screen Muffler cap Muffler band Muffler Refer to MUFFLER AND AIR CLEANER in CHAPTER 3 SVU2140 SVU2150...

Page 21: ...the piston to the top dead center of its compression stroke when the screw driver inserted into the spark plug hole reaches the highest position SVU2170 3 Measure Valve clearance Out of specification Adjust NOTE Valve clearance must be measured when the engine is cool to the touch Intake Valve cold 0 1 mm 0 004 in Exhaust Valve cold 0 1 mm 0 004 in Thickness gauge YU 26900 9 90890 03079 SVU2180 ...

Page 22: ... out to obtain the proper clearance Tighten the locknut 1 Adjuster Valve clearance Turn in Decrease Turn out Increase T R Locknut 10 Nm 1 0 m kg 7 2 ft lb SVU2200 SVU2210 5 Install Cylinder head cover Breather hose Spark plug Spark plug cap T R Cylinder head cover bolt 10 Nm 1 0 m kg 7 2 ft lb Spark plug 18 Nm 1 8 m kg 13 ft lb ...

Page 23: ...compression pull the recoil starter until the needle stops ris ing on the compression gauge WARNING To prevent sparking when cranking the engine ground the high tension cord Testing steps below minimum level Squirt a few drops of oil into the cylinder Measure the compression again Standard compression pressure 400 600 kPa 4 6 kg cm2 57 85 psi Reading Diagnosis If higher than without oil Worn cylin...

Page 24: ...Connect Inductive tachometer 1 Inductive tachometer YU 8036 A Engine tachometer 90890 03113 1 SVU2230 2 Inspect Rated engine speed Specified engine speed OK Out of specification Refer to TROU BLESHOOTING in CHAPTER 3 Inspection steps Operate the engine with no load Turn economy switch 1 to OFF a Measure the rated engine speed Rated engine speed 3 550 r min SVU2240 BREATHER HOSE 1 Inspect Breather ...

Page 25: ... dirt from falling into the engine 1 Remove Spark plug cap Spark plug 2 Inspect Electrode 1 Wear damage Replace Insulator color 2 3 Measure Spark plug gap a Use a wire gauge or thickness gauge Out of specification Regap If necessary clean the spark plug with a spark plug cleaner Standard spark plug with resistor BPR4ES NGK Spark plug gap 0 7 0 8 mm 0 028 0 031 in SVU2260 Before installing the spar...

Page 26: ...Start the engine Check that the engine stops when the switch is set to STOP b SVU2290 ECONOMY SWITCH 1 Check Economy switch 1 Checking steps Set the economy switch 1 to ON a Start the engine Turn the switch of the electric device con nected to the AC outlet ON and OFF to check whether the engine speed increases and decreases SVU2300 PILOT LIGHT 1 Check Pilot light 1 Checking steps Start the engine...

Page 27: ...RCUIT BREAKER 1 Check DC circuit breaker Checking steps Press the reset button 1 to the position of RESET a Connect the pocket tester DC 20 V Start the engine Set the economy switch to OFF Measure the DC voltage Set the reset button to OFF b Voltage is zero OK Pocket tester YU 03112 90890 03112 DC voltage More than 12 V at 3 550 r min with no load at AC output cur rent N AC OVER LOAD BATTERY CHARG...

Page 28: ......

Page 29: ... Remarks Control panel assembly removal Remove the parts in the order listed below 1 Control panel assembly 1 2 Wire harness 1 Disconnect all couplers and lead wires 3 Ground terminal 1 For installation reverse the removal pro cedure 9 8 7 0 2 3 4 5 6 3 2 3 2 1 1 SVU3010 3 ...

Page 30: ...ted below 1 Control panel 1 2 Engine switch 1 3 Economy switch 1 4 Oil warning light 1 5 Pilot light 1 6 Over load warning light 1 7 DC circuit breaker assembly 1 8 AC receptacle 20 A 1 9 AC receptacle 30 A 1 0 DC receptacle 12 V 10 A 1 For assembly reverse the disassembly procedure 9 8 7 0 2 3 4 5 6 3 2 3 2 1 1 SVU3010 ...

Page 31: ...tank removal Remove the parts in the order listed below Control panel assembly 1 Control box cover 1 2 Oil warning unit 1 3 Wire harness 1 Disconnect all couplers lead wires and connections 4 Fuel hose 1 Set the fuel cock OFF position 5 Fuel tank 1 For installation reverse the removal procedure SVU3020 5 4 1 2 7 Nm 0 7 m kg 5 1 ft lb 3 3 ...

Page 32: ...ctor 2 1 4 Muffler band 1 5 Muffler cup 1 6 Muffler screen 1 7 Spark arrester 1 8 Air filter case cover 1 9 Air filter element 1 10 Metal gasket 1 11 Plate 1 12 Air filter case 1 13 Breather hose 1 14 Gasket 1 For installation reverse the removal procedure 8 9 10 11 12 14 13 New 1 3 2 2 Nm 0 2 m kg 1 4 ft lb 4 Nm 0 4 m kg 2 9 ft lb 7 Nm 0 7 m kg 5 1 ft lb 10 Nm 1 0 m kg 7 2 ft lb 16 Nm 1 6 m kg 11...

Page 33: ...outside the spark arrester with the upper hole in the tail pipe Align the rim of the muffler cap 3 with the protrusion b of the tail pipe Contact the protrusion against the rim of the muffler cap 3 without allowing it to enter the slit T R Muffler band 4 Nm 0 4 m kg 2 9 ft lb SVU3050 1 2 SVU3060 4 3 2 Install Muffler nuts 1 and 2 Muffler bolts 3 and 4 NOTE Tighten the nuts and bolts to the specifi...

Page 34: ...I unit removal Remove the parts in the order listed below Air cleaner assembly Refer to MUFFLER AND AIR CLEANER Throttle control motor coupler Refer to CARBURETOR 1 Control unit cover 1 2 Control unit 1 3 AC CDI unit 1 For installation reverse the removal procedure 3 1 2 2 Nm 0 2 m kg 1 4 ft lb 10 Nm 1 0 m kg 7 2 ft lb SVU3080 ...

Page 35: ...d fuel tank assem bly Refer to CONTROL BOX COVER AND FUEL TANK Muffler assembly and air cleaner assembly Refer to MUFFLER AND AIR CLEANER Control unit and AC CDI unit Refer to CONTROL UNIT AND AC CDI UNIT Carburetor assembly Refer to CARBURETOR 1 Engine bracket 1 2 Engine assembly 1 For installation reverse the removal procedure SVU3090 2 1 7 Nm 0 7 m kg 5 1 ft lb 16 Nm 1 6 m kg 11 ft lb ...

Page 36: ...fer to CONTROL BOX COVER AND FUEL TANK Muffler assembly and air cleaner assembly Refer to MUFFLER AND AIR CLEANER Control unit cover and control unit Refer to CONTROL UNIT AND AC CDI UNIT Carburetor assembly Refer to CARBURETOR Recoil starter fan case cover and fan case Refer to RECOIL STARTER 1 Spark plug cap 1 2 Spark plug 1 3 Breather hose 1 4 Cylinder head cover 1 5 Gasket 1 6 Air shroud 1 7 C...

Page 37: ...3 9 ENG CYLINDER HEAD COVER AND CYLINDER HEAD Order Job name Part name Q ty Remarks 9 Dowel pin 2 10 Push rod 2 For installation reverse the removal procedure SVU3090 ...

Page 38: ...ustion chamber for car bon deposits Carbon deposits Remove NOTE Be sure not to damage the contact surface of the cylinder 2 Inspect Cylinder head Cracks damage around the hole of spark plug Replace 3 Measure Cylinder head warpage Measure the warpage on the contact surface of the cylinder head at six points using the straight edge and thick ness gauge Out of specification Resurface or replace Warpa...

Page 39: ...er head bolts 1 to 4 NOTE Tighten the bolts to the specified torque in two steps and in order from 1 to 4 T R Cylinder head bolts 20 Nm 2 0 m kg 14 ft lb SVU3140 BREATHER HOSE ASSEMBLY 1 Inspect Breather hose 1 NOTE Contact the end of the breather hose to the reed valve stopper a SVU3150 ...

Page 40: ...order listed below Cylinder head assembly Refer to CYLINDER HEAD COVER AND CYLINDER HEAD 1 Lock nut 2 2 Adjuster 2 3 Locker arm 2 4 Valve cotter 2 5 Valve spring retainer 2 6 Valve spring 2 7 Valve intake 1 8 Valve exhaust 1 9 Valve stem seal 1 For installation reverse the removal procedure SVU3160 ...

Page 41: ...53 90890 01253 SVU3170 VALVE AND VALVE SPRING INSPECTION 1 Measure Valve stem length a Valve face diameter b Out of specification Replace 2 Measure Valve stem diameter a Out of specification Replace Valve stem length Intake 65 9 mm 2 59 in Exhaust 66 2 mm 2 61 in Valve face diameter Intake 24 0 mm 0 94 in Exhaust 22 0 mm 0 87 in Valve stem diameter Intake and exhaust 5 5mm 0 22 in Wear limit Intak...

Page 42: ...th a Out of specification Replace Valve spring free length Intake and exhaust 26 5 mm 1 04 in Limit 25 0 mm 0 98 in SVU3210 5 Measure Valve spring tilt a Out of specification Replace Tilt limit 1 6 mm 0 06 in SVU3220 6 Inspect Valve spring contact surface More than 2 3 of the contact surface does not contact Replace SVU3230 LOCKER ARM INSPECTION 1 Inspect Locker arm Wear damage cracks Replace SVU3...

Page 43: ...ting the valve seat 4 Measure Valve face contact width a Make sure that the contact width along the entire valve face is within specifica tions Out of specification rough eccentric wear Replace Valve face contact width intake and exhaust 0 7 mm 0 03 in Limit 1 7 mm 0 067 in SVU3250 5 Measure Valve seat contact width a Make sure that the contact width along the entire valve seat is within specifica...

Page 44: ...APPING 1 Apply a coarse lapping compound evenly on the valve face Lap the valve by tap ping and rotating the valve lapper 1 clockwise and counterclockwise 2 Clean off all of the lapping compound from the valve face and valve seat Apply fine lapping compound on the valve face and lap the valve as in step 1 3 If the contact width on the valve face shines white along the entire face apply mechanic s ...

Page 45: ...Valve spring retainer 3 Valve cotter 4 Apply a small amount of molybdenum disulfide oil to the valve stem and use the valve spring compressor 5 to install the parts CAUTION Do not compress the valve spring more than necessary Valve spring compressor YM 01253 90890 01253 SVU3290 New ...

Page 46: ...ir cleaner assembly Refer to MUFFLER AND AIR CLEANER Control unit cover control unit Refer to CONTROL UNIT AND AC CDI UNIT Engine mount nut M6 Refer to ENGINE Carburetor assembly Refer to CARBURETOR 1 Recoil starter assembly 1 2 Fan case cover 1 3 Fan case 1 4 Starter pulley 1 5 Rectifier 1 6 Plate 1 For installation reverse the removal procedure 1 2 3 4 7 Nm 0 7 m kg 5 1 ft lb 2 3 Nm 0 23 m kg 1 ...

Page 47: ...ssembly Remove the parts in the order listed below 1 Starter handle 1 2 Bolt 1 3 Drive plate 1 4 Clip 1 5 Drive pawl 2 6 Spring 2 7 Sheave drum 1 8 Starter spring 1 9 Starter case 1 For assembly reverse the disassembly procedure R 1 8 9 7 4 5 6 3 2 B 5 Nm 0 5 m kg 3 6 ft lb SVU3310 ...

Page 48: ...e to the remove starter handle 1 1 SVU3320 2 Remove Drum sheave 1 CAUTION Be sure to press down on the drum sheave because the spring will spring out sud denly when it is removed from the sheave drum 1 SVU3330 3 Remove Starter spring 1 SVU3340 1 RECOIL STARTER INSPECTION 1 Inspect Starter rope 1 2 Inspect Starter spring 2 Damage deterioration Replace SVU3350 2 1 3 Inspect Drive pawl 1 Drive plate ...

Page 49: ... 1 Starter rope 2 Starter case 3 NOTE Wind the starter rope 2 clockwise two turns on the sheave drum 1 Engage starter spring inner hook a with the strut b of the starter case 3 and install the parts 1 2 SVU3370 1 2 3 SVU3380 3 Install Spring 1 Drive pawl 2 NOTE Install the spring 1 and drive pawl 2 to the R mark a 2 1 SVU3390 4 Install Clip 1 Drive plate 2 NOTE Align the groove a of the drive plat...

Page 50: ...htening the bolt place starter rope 2 in the cutout a in the sheave drum and wind it counterclockwise four turns 1 2 SVU3410 NOTE Make a knot b at the end of the starter rope to prevent the rope from being retracted into the recoil starter case SVU3420 ...

Page 51: ...ER Recoil starter fan case cover fan case Refer to RECOIL STARTER 1 Spacer 1 2 Fan 1 3 Ignition coil 1 4 Ground lead wire 1 5 Pulser coil 1 6 Magneto rotor 1 Remove the magneto rotor and stator coil assembly as a set 7 Tube 2 8 Stator coil assembly 1 9 Woodruff key 1 10 Clamp 1 6 7 7 1 2 8 10 12 11 9 12 3 5 4 4 Nm 0 4 m kg 2 9 ft lb 7 Nm 0 7 m kg 5 1 ft lb 10 Nm 1 0 m kg 7 2 ft lb 65 Nm 6 5 m kg 4...

Page 52: ... Q ty Remarks 11 Grommet 1 12 Dowel pin 2 For installation reverse the removal procedure 6 7 7 1 2 8 10 12 11 9 12 3 5 4 4 Nm 0 4 m kg 2 9 ft lb 7 Nm 0 7 m kg 5 1 ft lb 10 Nm 1 0 m kg 7 2 ft lb 65 Nm 6 5 m kg 47 ft lb SVU3430 GENERATOR ...

Page 53: ...1 2 1 SVU3440 2 Remove Stator coil assembly bolts 1 NOTE Turn the magneto rotor until the stator coil assembly bolts are visible through the holes in the rotor and then remove the bolts SVU3442 1 3 Remove Stator coil assembly bolts 2 Tubes NOTE Turn the magneto rotor until the stator coil assembly bolts are visible through the holes in the rotor and then remove the bolts Align the keyway a of the ...

Page 54: ...ION The magnetic force of the magneto rotor is very strong Therefore do not change the position of the magneto rotor and stator coil assembly during or after removal oth erwise they may be damaged Rotor puller YU 33270 90890 01362 1 2 SVU3450 MAGNETO ROTOR AND STATOR COIL ASSEMBLY INSTALLATION 1 Install Woodruff key 1 CAUTION Be sure to remove any oil or grease from the tapered portion of the magn...

Page 55: ...embly bolts are visible though the holes in the rotor and then remove the bolts 1 Align the keyway a of the magneto rotor with the stator coil assembly bolts 1 so that they are in a straight line The piston is at top dead center when keyway and bolts are in this position T R Stator coil assembly bolts 10 Nm 1 0 m kg 7 2 ft lb SVU3465 1 1 a 4 Tighten Magneto rotor nut 1 Washer NOTE Tighten the magn...

Page 56: ...ngine assembly Refer to ENGINE Cylinder head assembly Refer to CYLINDER HEAD COVER AND CYLINDER HEAD Recoil starter fan case cover fan case fan magneto rotor and stator coil Refer to RECOIL STARTER and GEN ERATOR 1 Crankcase cover 1 2 Gasket 1 3 Dowel pin 2 4 Bracket 1 5 Oil level switch 1 6 Camshaft 1 7 Valve lifter 2 8 Bracket 1 For installation reverse the removal procedure SVU3490 ...

Page 57: ...length Intake a 26 9 0 05 mm 1 06 0 002 in b 22 0 0 05 mm 0 87 0 002 in Exhaust a 26 68 0 05 mm 1 05 0 002 in b 22 03 0 05 mm 0 87 0 002 in SVU3510 3 Inspect Surface of camshaft gear teeth Decompressor Wear damage Replace SVU3520 4 Measure Camshaft diameter a Out of specification Replace Camshaft diameter 14 965 14 990 mm 0 5892 0 5902 in Wear limit 14 950 mm 0 59 in SVU3530 ...

Page 58: ...t gear mark b SVU3550 CRANKCASE COVER INSPECTION 1 Inspect Crankcase cover 1 Damage Replace Bearing 2 Noise wear rotational failure Replace 1 2 SVU3560 CRANKCASE COVER INSTALLATION 1 Install Crankcase cover bolts 1 to 6 NOTE Tighten the bolts to the specified torque in two steps and in order from 1 to 6 T R Crankcase cover bolts 22 Nm 2 2 m kg 16 ft lb SVU3570 CRANKCASE COVER AND CAMSHAFT ...

Page 59: ...to ENGINE Cylinder head assembly Refer to CYLINDER HEAD COVER AND CYLINDER HEAD Recoil starter fan case cover and fan case Refer to RECOIL STARTER Fan magneto rotor and stator coil assembly Refer to GENERATOR Crankcase cover and camshaft Refer to CRANKCASE COVER AND CAMSHAFT 1 Connecting rod cap 1 2 Crankshaft 1 3 Connecting rod 1 4 Piston pin circlip 2 5 Piston pin 1 6 Piston 1 7 Piston ring 3 Fo...

Page 60: ...ide diameter 66 00 66 02 mm 2 5984 2 5990 in Cylinder inside diameter wear limit 66 020 mm 2 5990 in Cylinder taper limit 0 05 mm 0 002 in SVU3590 2 Measure Cylinder warpage NOTE Measure the warpage on the contact surface of the cylinder head at six points using a straight edge and thickness gauge Out of specification Resurface or replace Warpage limit 0 05 mm 0 002 in SVU3600 PISTON AND PISTON PI...

Page 61: ...e Piston pin hole inside diameter 16 002 16 013 mm 0 6300 0 6304 in Wear limit 16 020 mm 0 6307 in SVU3620 4 Measure Piston pin diameter Out of specification Replace Piston pin diameter 15 995 16 000 mm 0 6297 0 6299 in Wear limit 15 950 mm 0 6280 in SVU3630 5 Inspect Check that the piston pin enters smoothly into the piston pin hole If the piston pin fits tightly into the pis ton check the piston...

Page 62: ... 0 2 0 4 mm 0 008 0 016 in 0 9 mm 0 0354 in Oil ring 0 2 0 4 mm 0 008 0 016 in 0 9 mm 0 0354 in SVU3650 2 Measure Piston ring side clearance Out of specification Replace Use a thickness gauge 1 NOTE Clean carbon deposits from the piston ring grooves and rings before measuring the side clearance Measure the side clearance at several portions Piston ring side clearance Wear limit Top ring 0 04 0 08 ...

Page 63: ... 27 9 mm 1 098 in SVU3690 CONNECTING ROD OIL CLEARANCE INSPECTION NOTE Measure the oil clearance if replacing the crankshaft or connecting rod 1 Place a piece of Plastigauge 1 on the crank pin horizontally NOTE Clean off oil from all parts thoroughly 2 Install Connecting rod 1 Connecting rod cap 2 NOTE Tighten the cap bolts so that the crankshaft does not move while the oil clearance is being meas...

Page 64: ...n SVU3720 PISTON RING AND PISTON ASSEMBLY 1 Install Top ring 1 2nd ring 2 Oil ring 3 NOTE Be sure to install the second ring so that the manufactures mark a faces towards the piston head Make sure that the piston rings move smoothly 2 Apply 4 stroke engine oil to the inside of the connecting rod small end 3 Install Piston 1 Piston pin 2 Piston pin circlip 3 NOTE Make sure that the YAMAHA mark a on...

Page 65: ...8 SVU3760 3 Install Connecting rod 1 Piston 2 NOTE Make sure that the mark a on the pis ton head faces toward the push rod Make sure that the YAMAHA mark b on the connecting rod faces toward the crank case cover 4 Install Crankshaft Connecting rod cap NOTE Make sure that the mark a on the con necting rod is aligned with the mark b on the rod cap 5 Install Camshaft Crankcase cover Refer to CRANKCAS...

Page 66: ...he order listed below Air cleaner assembly Refer to MUFFLER AND AIR CLEANER 1 Choke knob 1 2 Choke cable 1 3 Fuel hose 1 4 Throttle control motor cover 1 5 Throttle control motor coupler 1 6 Carburetor assembly 1 7 Gasket 1 8 Carburetor joint 1 9 Gasket 1 For installation reverse the removal procedure SVU3790 ...

Page 67: ...e order listed below 1 Throttle control motor assembly 1 2 Throttle controller bracket 1 3 Bracket 1 4 Bolt 1 5 Gasket 1 6 Drain screw 1 7 Float chamber 1 8 Gasket 1 9 Float pin 1 0 Float 1 A Needle valve 1 B Main nozzle 1 C Main jet 1 D Pilot jet 1 For assembly reverse the disassembly procedure SVU3800 ...

Page 68: ...y contacts the float arm and then measure the float height a This measure ment should be made with the gasket removed Float height 16 0 mm 0 63 in SVU3810 SVU3820 2 Clean Carburetor body Blow out all passages jets and carbu retor body with compressed air SVU3830 3 Inspect Valve seat Wear damage Replace Dirt Clean 1 Wear at groove 2 Dirt SVU3840 CARBURETOR ...

Page 69: ... choke valve in its fully open position a insert the tip of the inner cable into drum hole 5 and then secure it in place with the screw 6 T R Screw 1 Nm 0 1 m kg 0 7 ft lb SVU3850 THROTTLE CONTROL MOTOR 1 Inspect Throttle control motor 1 NOTE Install the shaft a of the throttle control motor by aligning it with the groove b of the throttle shaft Install the throttle valve and then make sure that i...

Page 70: ...ck lever posi tion ON OFF Set to ON Check if fuel travels to fuel cock Clean fuel tank and fuel cock GOOD NOT GOOD Check spark plug for dirt and check spark plug gap Check for voltage leakage due to faulty connection or broken insulation of the high tension cord Check AC CDI unit connector for corro sion or faulty connection Check the ignition system Refer to IGNITION SYSTEM in CHAPTER 4 Remove sp...

Page 71: ...e OUT OF SPECIFICA TION GOOD Check valve face and valve seat for wear GOOD WEAR Resurface or replace Check if the timing marks on the crankshaft and cam shaft are aligned GOOD NO GOOD Correct or replace Check if there is seizure or wear on the piston piston ring or cylinder GOOD SEIZURE OR WEAR Rebore or replace Check the condition of the throttle control system Refer to THROTTLE CONTROL SYS TEM ...

Page 72: ...tor joint or gas ket Tighten the carbu retor bolts securely Replace carbure tor joint or gasket with a new one GOOD NO GOOD Measure valve clearance GOOD OUT OF SPECIFICA TION Adjust Check compression using a compression gauge GOOD OUT OF SPECIFICA TION Improperly tight ened cylinder head Tighten securely Check if there is proper clearance between pulser coil and magneto rotor GOOD OUT OF SPECIFICA...

Page 73: ... clogged GOOD NO GOOD Disassemble or clean Check for air suction due to a damaged throttle shaft seal car buretor joint or gasket GOOD NO GOOD Disassemble or replace Check compression using com pression gauge GOOD TOO HIGH Decarbonize combustion chamber if there are carbon deposits TOO LOW Check valve face and valve seat for wear GOOD WEAR Resurface or replace Check if the timing marks on the cran...

Page 74: ...just Measure valve clearance GOOD OUT OF SPECI FICATION Adjust While the engine is operating pull the choke knob approximately 1 3 to 1 2 way out and then check the engine operating condition STABLE UNSTABLE Inspect from Check for air suction due to a damaged throttle shaft seal car buretor joint or gasket GOOD NO GOOD Disassemble or replace Check if slow or main passages such as the pilot jet and...

Page 75: ...nd valve seat for wear GOOD WEAR Resurface or replace Check if there is seizure or wear on piston piston ring or cylinder GOOD SEIZURE OR WEAR Rebore or replace Check the condition of the throttle control system Refer to THROTTLE CONTROL SYSTEM ...

Page 76: ...if it turns smoothly with slight resistance GOOD NO GOOD Replace the throttle control motor Measure the coil resistance between 3 1 3 2 3 4 and 3 5 of the throttle control motor Tester range Ω 100 250 Ω 7 25 C 77 F GOOD OUT OF SPECIFI CATION Replace the throttle control motor Check the connections of the wire har ness connectors and couplers and the wires for an open circuit or short circuit GOOD ...

Page 77: ...ase when economy control switch is set to ON Check AC output GOOD NO GOOD Refer to GENERATOR SYSTEM in CHAPTER 4 Check condition of the throttle con trol motor GOOD NO GOOD Replace throttle control motor Check economy switch GOOD NO GOOD Replace economy switch Check the connections of the wire harness connectors and couplers and the wires for an open circuit or short circuit GOOD NO GOOD Correct o...

Page 78: ...ight Red 9 Pilot light Green 0 Oil warning light Red A Oil level switch B DC circuit breaker C Spark plug D Throttle control motor E Pulser coil F Magneto rotor G Stator coil assembly H AC CDI unit I Ignition coil J DC receptacle 12 V 10 A K Rectifier SVU4010 SVU4020 ECON SW AC OVER LOAD BATTERY CHARGE ONLY 12V10A RESET AC RESET METHOD ENGINE PAUSE 20A OFF DC PROTECTOR DC AC 7VU 40 0 9 B 6 5 7 J 8...

Page 79: ...IAGRAM 1 Main coil 2 Sub coil AC control 3 Charge coil ignition source 4 Generator assembly 5 Control unit 6 Pilot light 7 AC receptacle 20 A 8 AC receptacle 30 A 9 Ground terminal 0 DC charge coil A Economy switch B Overload warning light C Engine switch D Oil warning light E Oil warning unit F Oil level switch G Spark plug H Ignition coil I AC CDI unit J Pulser coil K Throttle control motor L Re...

Page 80: ...ty If the continuity is faulty at any point replace the switch NOTE Set the pocket tester to 0 before starting a test When testing the switch for continuity the pocket tester should be set to the 1 Ω range When checking the switch turn it on and off a few times Pocket tester YU 03112 90890 03112 SVU4050 ...

Page 81: ...for troubleshooting NO SPARK OR WEAK SPARK Pocket tester YU 03112 90890 03112 Dynamic spark tester YM 34487 Ignition checker 90890 06754 GOOD 1 Spark plug Check the spark plug condition Refer to SPARK PLUG in CHAPTER 2 NO GOOD Repair or replace the spark plug 2 Ignition spark gap Disconnect the spark plug cap 1 from the spark plug Connect the dynamic spark tester 2 or ignition checker 3 as shown S...

Page 82: ... the plug cap from the high tension cord Remove Turn the plug cap counterclock wise Install Turn the plug cap clockwise Inspect the high tension cord for cracks or deterioration when install the pug cap Cut 5 mm off the end of the high tension cord and then connect it to the plug cap OUT OF SPECIFICATION Replace the spark plug cap MEETS SPECIFICATION 4 Ignition coil resistance Remove the ignition ...

Page 83: ...il 1 Connect the pocket tester Ω 1 to the secondary terminal Tester lead Red terminal 2 Tester lead Green Yellow terminal 3 Charge coil resistance 0 5 Ω 10 at 20 C 68 F OUT OF SPECIFICATION Replace the stator coil assembly SVU4100 Or Or Or Or G Y G Y R R 1 2 3 C0NTINUITY 6 Pulser coil resistance Disconnect the pulser coil coupler 1 Connect the pocket tester Ω 100 to the secondary terminal Tester l...

Page 84: ...inal Switch ON Continuity Turn the engine stop switch to STOP b and then check the engine stop switch for continuity Switch STOP No continuity NO CONTINUITY CONTINUITY Replace the engine switch SVU4120 CONTINUITY 8 Oil level switch Remove the oil level switch from the bot tom of the crankcase Refer to CRANKCASE COVER AND CAMSHAFT in CHAPTER 3 Connect the pocket tester to the oil level switch for c...

Page 85: ...ON SYSTEM C0NTINUITY GOOD GOOD 9 Wire harness Check the terminal of the connector for contamination rust or disconnection Replace the magneto rotor Replace the AC CDI unit DISCONNECTED Correct or replace the connector ...

Page 86: ...LE CONTROL SYSTEM in CHAP TER 3 Main coil AC voltage inspection Disconnect the sub coil coupler 1 Connect the Red and Green Yellow leads and then connect the Orange leads Disconnect the main coil coupler Start the engine Connect the pocket tester to the Yellow leads Measure the voltage Tester range AC 300 V Main coil AC voltage 160 200 V GOOD TOO LOW DOES NOT GENERATE Or Or G Y G Y R R G Y R Or Or...

Page 87: ...U4180 Magnetic force is weak Replace the magneto rotor Sub coil resistance inspection Stop the engine Measure the resistance between the Orange to Orange lead Tester range Ω 1 Sub coil resistance 0 14 Ω 10 at 20 C 68 F GOOD DISCONNECTED SHORT CIRCUIT Replace the stator coil assembly Or Or G Y G Y R Or Or R 1 SVU4190 Economy switch continuity inspection Switch ON Continuity Switch OFF No Continuity...

Page 88: ...eter 90890 03113 C0NTINUITY 1 Battery voltage Connect the pocket tester to the battery termi nals Measure battery voltage Tester lead terminal Tester lead terminal Sub coil AC voltage 11 8 V Measure the specific gravity Specific gravity 1 280 OUT OF SPECIFICATION Clean the terminals Recharge or replace the battery C0NTINUITY 2 Charging voltage Start the engine Set the economy switch to OFF 3 550 r...

Page 89: ...ints Pocket tester connecting point Continuity Red Black Red terminal 2 Blue terminal 4 NO Blue terminal 4 Red terminal 2 YES Red terminal 2 Blue terminal 5 NO Blue terminal 5 Red terminal 2 YES Black terminal 3 Blue terminal 4 YES Blue terminal 4 Black terminal 3 NO Black terminal 3 Blue terminal 5 YES Blue terminal 5 Black terminal 3 NO NO GOOD Replace the rectifier R B L L B R 1 4 5 3 2 3 4 2 1...

Page 90: ...ed r min 3 550 Operating hours 60 Hz Hrs W no load 24 9 W rated load 7 7 Fuel Unleaded regular gasoline Fuel tank capacity L Imp gal US gal 9 0 1 97 2 38 Engine oil capacity L Imp qt US qt 0 6 0 53 0 63 Engine oil grade 4 stroke engine oil API service classification SE or SF if not available SD Electrical Ignition system AC CDI Voltage Ignition timing BTDC 23 1 Spark plug type BPR4ES NGK Gap mm in...

Page 91: ...pe AC Electronic no fuse breaker DC Circuit breaker No fuse breaker Rated engine speed r min 3 550 Voltage regulation Voltage feed back system Voltage stability Within 1 Frequency stability Hz Within 0 1 Rotating speed control Throttle motor control type Wave distortion ratio Less than 2 5 Number of phase Single phase Insulation resistance MΩ Over 10 Insulation type E type Receptacle AC 20 A Duple...

Page 92: ...t 15 950 0 6280 Piston ring mm in Top ring Type Barrel face Dimensions B T 1 5 2 7 0 059 0 106 End gap 0 2 0 4 0 008 0 016 Limit 0 9 0 0354 Side clearance 0 04 0 08 0 0016 0 0031 Limit 0 1 0 0039 2nd ring Type Taper Dimensions B T 1 5 2 7 0 059 0 106 End gap 0 2 0 4 0 008 0 016 Limit 0 9 0 0354 Side clearance 0 02 0 06 0 0008 0 0024 Limit 0 1 0 0039 Oil ring Type Solid Dimensions B T 2 5 2 7 0 098...

Page 93: ...ter Cam dimension IN EX A 26 9 0 05 1 06 0 002 26 68 0 05 1 05 0 002 B 22 0 0 05 0 87 0 002 22 03 0 05 0 87 0 002 Camshaft journal 14 965 14 990 0 5892 0 5902 Limit 14 950 0 59 Valve mm in Valve Face diameter A IN 24 0 0 94 EX 22 0 0 87 Stem diameter B IN 5 5 0 22 EX 5 5 0 22 Stem lengtlh C IN 65 9 2 59 EX 66 2 2 61 Valve face contanct width D IN 0 7 0 03 EX 0 7 0 03 Limit 1 7 0 067 Valve stem run...

Page 94: ... IN 21 6 0 85 EX 21 6 0 85 Set force IN 4 5 kg 9 9 lb EX 4 5 kg 9 9 lb Tilt limit 1 6 0 06 Carburetor mm in Type manufacture BV20 15 MIKUNI I D mark 7VU 10 Bore size ø15 Main jet 88 8 Min air jet ø1 8 0 0709 Pilot air jet ø1 1 0 0433 Pilot outlet ø0 9 0 0354 Valve seat size ø1 8 0 0709 Main nozzle 31B Pilot jet 37 5 Throttle valve 150 Float height H 16 0 0 63 Unit EF2800i ...

Page 95: ...motor coupler dis connected 13 5 23 0 2 800 Coil resistance Main coil Ω 10 0 6 Yellow Yellow Sub coil Ω 10 0 14 Orange Orange DC charge coil Ω 10 0 5 Blue Blue Electrical Ignition system AC CDI voltage Pulser coil resistance Ω 20 185 Ignition timing at 3 800 r min BTDC 23 Primary coil resistance Ω 15 0 11 Secondary coil resistance kΩ 20 6 7 Charge coil resistance Ω 10 ignition source 0 5 Spark plu...

Page 96: ...4 Muffler nut M6 1 0 7 0 7 5 1 Muffler bolt M6 1 0 10 1 0 7 2 Muffler protector 1 2 M6 1 0 10 1 0 7 2 Muffler stay M8 1 25 16 1 6 11 Muffler band M5 0 8 4 0 4 2 9 Engine mount nut M6 1 0 7 0 7 5 1 Engine mount bolt M8 1 25 16 1 6 11 Ground lead wire bolt frame M6 1 0 7 0 7 5 1 Recoil starter M6 1 0 7 0 7 5 1 Fuel tank M6 1 0 7 0 7 5 1 Fuel cock cup 1 3 0 13 0 94 Choke cable tightening screw 1 0 1 ...

Page 97: ...treads Components should be at room temperature DEFINITION OF UNITS Tread size Tightening torque Nm m kg ft lb M4 2 0 2 1 4 M5 3 0 3 2 2 M6 7 0 7 5 1 M7 10 1 0 7 2 M8 15 1 5 11 M10 30 3 0 22 M12 60 6 0 43 Unit Read Definition Measure mm Millimeter 10 3 meter Length cm Centimeter 10 2 meter Length kg Kilogram 103 gram Weight N Newton 1 kg m sec2 Force Nm Newton meter N m Torque m kg Meter kilogram ...

Page 98: ...ESET METHOD ENGINE PAUSE 20A OFF DC PROTECTOR DC AC 7VU 40 C C Y R R R B B B R L R Br Y B W B W B Br Br Br Br R R R R Gy Gy Gy B W G Y Y R Br SVU5010 È Black lead with red tape mark É Black White and Yellow leads with tape mark Ê Ground terminal COLOR CODE B Black Br Brown L Blue Gy Gray R Red Y Yellow B W Black White G Y Green Yellow SVU5020 SVU5030 ...

Page 99: ...e clamp through the hole of the fan case cover and then fasten the lead wires Ê Connect the coupler and then store them in the space located above the control unit Ë Coupler storage space Ì Connect the lead wires and then fasten them with a clamp Í Store the AC CDI connector red vertically along the end of the storage space SVU5040 WIRE ROUTING DIAGRAM ...

Page 100: ...plug cap É Route the oil level switch lead as shown Ê Pass the leads through the hole install and tighten the clamp and then insert it in the grom met into the hole Ë Connect the ground lead connector to the igni tion coil and then tighten the ground lead termi nal together with the pulser coil SVU5050 WIRE ROUTING DIAGRAM ...

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Page 102: ...PRINTED ON RECYCLED PAPER PRINTED IN USA YAMAHA MOTOR CO LTD E ...

Page 103: ...E B Black Br Brown G Green Gy Gray L Blue R Red W White Y Yellow Or Orange B W Black White G Y Green Yellow W L White Blue 1 Main coil 2 Sub coil AC control 3 Charge coil Ignition source 4 Generator assembly 5 Control unit 6 Pilot light 7 AC receptacle 20 A 8 AC receptacle 30 A 9 Ground terminal 0 DC charge coil A Economy switch B Over load warning light C Engine switch D Oil warning light E Oil w...

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