Rato R5500 User manual

R5500 ·R5500D
SERVICE MANUAL
CHONGQING RATO POWER.CO., LTD

This manual contains information how to maintain and how to do troubleshooting.
Keep this owner’s manual handy, so you can refer to it at any time.
This service manual describes correct method of the maintaining this equipment. As a result
of this disregard of our rules caused by person casualty and equipment damaged, our
company does not assume any responsibility.
NOTICE：
Copyright reserved, and no part of this publication may be reproduced without our
Company’s written permission.

SAFETY MESSAGES
Your safety and the safety of others are very important. We have provided important safety
messages in this manual and on the generator. Please read these messages carefully.
A safety message reminds you to potential hazards that could hurt you or others. Each safety
message is preceded by a safety alert symbol and one of three words: DANGER,
WARNING, or CAUTION. These mean:
You WILL be KILLED or SERIOUSLY HURT if you don’t follow
instructions.
You CAN be KILLED or SERIOUSLY HURT if you don’t follow
instructions.
You CAN be HURT if you don’t follow instructions.
Your generator or other property could be damaged if you don’t
follow instructions.

1. PREFACE
1
1. PREFACE
1-1 Generator Component Identification
FUEL METER FUEL TANK CAP
SPARK PLUG CAP
MUFFLER
RECOIL STARTER GRIP
CHOCKER LEVER
AC CIRCUIT BREAKER
DC PROTECTOR
FUEL VALVE
GROUND TERMINAL
AC RECEPTACLES
AIR CLEANER
GENERATOR SWITCH
DC RECEPTACLES
VOLTMETER

1. PREFACE
3
1-2 Specifications
Remarks: ●means available, - means unavailable
Item R5500 R5500D
Gasoline
Engine
Gasoline Engine Style R390 R390-3
Gasoline Engine Type Single Cylinder, 4-Stroke, Forced Air Cooling, OHV
Displacement (ml) 389
Igniting System Transistorized Magneto
Fuel Volume (L) 25
Fuel
Consumption(g/(kW·h) ≤374 ≤374
Continuing Time (hr) ９
Oil Capacity (L) 1.1
Generato
r
Charging Voltage (DC) (V) 12
Charging Current (DC) (A) 8.3
Rated Frequency (Hz) 50
Rated Voltage (V) 220/230
Rated Output Power (kW) 5
Maximum Output Power
(kW) 5.5
Battery(rated capacity)(AH) - 11
Battery(voltage)(V) - 12
Generato
r Set
Length (mm) 683
Width (mm) 540
Height (mm) 542
Net Weight (kg) 82 86
Phase Single
General-
Purpose
Accessor
y
Large Air Cleaner ● ●
Large Muffler ● ●
Large Fuel Tank ● ●
Fuel Gauge ● ●
Voltmeter ● ●
Automatic Voltage
Regulator(AVR) ● ●
Oil Alert System ● ●
Non-fuse Breaker ● ●
Electric Starting Accessory - ●

1. PREFACE
4
1-3 Maintenance Standard
Engine
Parts Item Standard Service Limit
Gasoline
Engine
Maximum Speed (No load)
Cylinder Compression
3180-3780 rpm
≥588-834Mpa（600rmp）
--
--
Cylinder Sleeve I.D 88.00mm 88.17mm
Cylinder
Head Cover Warpage -- 0.10mm
Piston
Skirt O.D.
Piston-to-Cylinder Clearance
Piston Pin Bore I.D.
Piston Pin O.D
Piston Pin-to-Piston Pin Bore Clearance
87.985mm
0.015-0.02mm
20.002mm
20.00mm
0.002-0.014mm
87.85mm
0.12mm
20.042mm
19.95mm
0.08mm
Piston
Rings
Ring Side Clearance：
Second
Ring Enc Gap:
Second
Ring Width：
Second
0.030-0.060mm
-
0.20-0.40mm
0.2-0.7mm
2.0mm
0.15mm
-
1.0mm
1.0mm
1.75mm
Connecting
Rod
Small End I.D
Big End I.D
Big Oil Clearance
Big End Side Clearance
20.005mm
36.025mm
0.040-0.066mm
0.1-0.7mm
20.07mm
36.07mm
0.12mm
1.0mm
Crankshaft Crankshaft Pin O.D 35.985mm 35.93mm
Valve
Valve Clearance
Stem O.D
Guide I.D
Stem Clearance
Seat Width
Spring Free Length
IN
EX
IN
EX
IN
EX
0.15±0.02mm
0.20±0.02mm
6.59mm
6.55mm
6.60mm
0.010-0.040mm
0.050-0.080mm
1.1mm
39.0mm
--
--
6.44mm
6.40mm
6.66mm
0.11mm
0.13mm
2.0mm
37.5mm

1. PREFACE
5
Camshaft
Cam Height
Cam Height
Journal O.D
IN
EX
32.40-32.80m
31.89-32.29mm
15.984mm
32.25mm
31.75mm
15.92mm
Crankcase
Cover Camshaft Bracket I.D 16.0mm 16.05mm
Carburetor
Main Jet
Float Height
Pilot Screw Opening
#102
13.2mm
2-1/4
--
--
--
Spark Plug Gap 0.7-0.8mm --
Spark Plug
Cap Resistance 7.5-12.5kΩ--
Ignition Coil
Resistance
Air Gap
Primary Coil
Secondary Coil
0.8-1.0Ω
5.9-7.1kΩ
0.4-0.6mm
--
--
--
Generator
Parts Item Standard Service Limit
Stator Winding Resistance
Stator Winding 0.6±10%Ωat 20℃--
Stator Auxiliary Winding 2.6±10%Ωat 20℃时 --
Rotor Excitation
Winding Resistance Excitation Winding
63.5±10%Ωat 20℃时 --
Carbon Brush Carbon Brush Length 10mm 10mm 6mm

2. MAINTENANCE
6
2. MAINTENANCE
2-1 Maintenance Schedule
Good maintenance is essential for safe, economical, and trouble-free operation. It will also
help reduce air pollution.
Exhaust gas contains poisonous carbon monoxide. Shut off the
engine before performing any maintenance. If the engine must be
run, make sure the area is well ventilated.
Periodic maintenance and adjustment is necessary to keep the generator in good operating
condition. Perform the service and inspection at the intervals shown in the Maintenance
schedule below:
REGULAR SERVICE PERIOD Each
use
First month
or 20 Hrs.(3)
Every 3
months or 50
Hrs. (3)
Every 6
months or 100
Hrs. (3)
Every year or
300 Hrs. (3)
Engine Oil Check level ○
Change ○○
Air Cleaner Check ○
Clean ○(1)
Sediment Cup Clean ○
Electrolyte Level Check ○
Spark Plug Clean ○renew
Valve Clearance Check-Adjust ○(2)
Cylinder Head Clean Every 300 hours (2)
Fuel Tank And
Strainer Clean Every 2 years (2)
Fuel Line Replace Every 2 years (2)
(1) Service more frequently when used in dusty areas.
(2) These items should be serviced by an authorized generator dealer.
(3) When more often use, only servicing according to above correct intervals can insure the
generator set long-term use.

2. MAINTENANCE
7
2-2 Engine Oil
CHANGE THE OIL
Draining can be performed rapidly and
completely while the gasoline engine is
still warm.
1) Remove the oil dipstick and drain
plug to drain the oil.
2) Reinstall the drain plug, and then
tighten the plug securely.
The torque of drain plug: 22±2N.m
3) Refill oil to the standard ( as shown in the right picture)and check the oil level.
4) Reinstall the oil dipstick.
Using engine oil may cause skin cancer if repeatedly let it contact
with the skin for prolonged periods. Although this is unlikely that
you hardly used oil on a daily basis, it is still advisable to thoroughly wash your hands
with soap and water as soon as possible after handling used oil.
Please dispose of used engine oil in a manner that is compatible with the environment. We
suggest you take it in a sealed container to your local service station or recycling center for
reclamation. Do not throw it in the dust heap or pour it on the ground.
2-3 Air Cleaner Service
A dirty air cleaner will restrict air flow to the carburetor. To prevent carburetor malfunction,
service the air cleaner regularly. Service more frequently when operating the generator in
extremely dusty areas (the period is shown in the 2-1 maintenance list, operating as follow.).
Using gasoline or flammable solvent to clean the filter element can
cause a fire or explosion. Only use soapy water or nonflammable
solvent.
Never run the generator without the air cleaner. Rapid engine wear
DRAIN PLUG
LOWER LEVEL
UPPER LEVEL
OIL DIPSTICK

2. MAINTENANCE
8
will result.
1) Remove the air cleaner clip or butterfly nut and open the air cover. Check the air cleaner
element for complete and clean.
2) If the air cleaner element is dirty, please clean the air cleaner element:
Wash the air cleaner element in a solution of household detergent and warm water, then
rinse thoroughly or wash in nonflammable or high flash point solvent: Drop a few points
engine oil in, then, squeeze out.
3) Reinstall the air cleaner element and the cover.
2-4 Fuel Sediment Cup Cleaning
1) Turn the fuel valve to the OFF position.
Remove the sediment cup, o-ring and strainer
( according to the arrowhead position).
2) Clean the sediment cup, and o-ring, and strainer
in nonflammable or high flash point solvent.
3) Reinstall o-ring, and strainer and screw down
the sediment cup.
4) Turn the fuel valve to the ON and check for
leaks.
ELEMENT
AIR CLEANER COVER
CLIP
AIR CLEANER
ELEMENT
STRAINE
0-RING
SEDIMENT
FUEL VALVE
SEDIMENT

2. MAINTENANCE
9
2-5 Spark Plug Service
Recommended spark plugs: F7RTC or other equivalents
1) Remove the spark plug cap.
2) Use the plug wrench to remove the spark plug.
3) Visually inspect the spark plug if the insulator is
cracked, if cracked, replace with a new spark plug.
4) Measure the plug gap with a feeler gauge. Correct as
necessary by carefully bending the side electrode. The gap
should be: 0.70-0.80 mm
5) Check that the spark plug washer is in good condition.
6) Install the spark plug on and screw down it with plug wrench,
compress the plug washer. Cover the spark plug cap on.
To avoid cross-threading, first, screw in spark plug by
hand, then tighten with a spark plug wrench to compress
the gasket ( according to the arrowhead picture).
If use a new spark plug, more twist 1/2 turns after
compressing the gasket
If reinstalling the used spark plug, just more twist 1/8-1/4
turns.
Spark plug torque value：22±2N·m.
SPARK PLUG CAP
PLUG WRENCH

2. MAINTENANCE
10
2-6 Valve Clearance Adjustment
Keep the clearance between engine valve rod end and driving parts for avoiding heat
expanding and cold shrinking to effect engine performance. If the clearance is too big, it can
result in exhausting unsmooth, effecting engine performance and increasing engine
noise(valve abnormal), if the clearance is too small, the valve will close untight to make the
engine operating abnormal and drain valve operating face burn. After operating one year or
300h, check and adjust the valve.
Dismount the cylinder head cover, gasket, spark plug, and spark plug cap in order.
Light pull the recoil starter rope lightly until the piston compressed to dead point of the
stroke.
Measure the valve clearance
FEELER
SPARK
PLUG
SPRAK
PLUG CAP BREATHE TUBE
CYLINDER
HEAD COVER
CYLINDER HEAD COVER
GASKET

2. MAINTENANCE
11
Adjust if the valve clearance is out of the service limit.
Measure the valve clearance in the cold the gasoline engine state.
Adjusting valve clearance
Valve clearance adjustment method: Loose the locking nut, turn the adjusting nut to get the
correct valve clearance. Screw down the locking nut
Valve clearance
IN 0.15±0.02mm
EX 0.20±0.02mm
Adjusting nut Valve clearance
Screw down Small
Screw off Big
CAUTION:
Clearance too big: Intake and exhaust valve opening delay will shorten the intake and
exhaust time, lower the opening height of the valve and change normal distributing
phase to result in power lowering from the intake lack and exhaust uncompleted.
Furthermore, also make vale train parts knock increasing and wearing quick.
Clearance too small: After running, gasoline engine parts will be heated to expand and
push the valve open, making the gasoline engine closing not tight and result in leaking,
power lowering, serious carbon deposit or burn on the valve surface, even valve
impacting the piston.
VALVE ADJUSTING NUT
VALVE LOCKED NUT

2. MAINTENANCE
12
2-7 Governor
①Reassembly or disassembly
GOVERNOR ROD
SCREW (M5×25)
STOPPER SPRING
THROTTLE PLATE
PIN
BOLT (M6×10)
RETURN SPRING
(install the short end
against the adjust
support)
NUT（M6）
GOVERNOR BRACKET
BOLT (M6×10)
GOVERNOR SPRING
((install the short end
against the adjust
support)
FIXING BOLT

2. MAINTENANCE
13
②Governor adjustment：
a) Dismount the fuel tank
b) Loosen the nut M6. Be sure that the carburetor throttle valve is fully open
c) Rotate the governor arm shaft fully to the right (governor fully closed position), and
retighten the nut.
TORQUE VALUE: 10N.m
d) Check to see that the governor arm and throttle valve move freely.
e) Check the maximum engine speed
③Maximum speed adjustment:
a) Start the gasoline engine and allow it to warm up to normal operating temperature.
b) If the maximum speed not conforming to specified value, adjust the adjusting bolt M5×25
Engine maximum speed：
Gasoline Engine maximum speed 3180 -3780rpm
Speed too big Turn the adjusting bolt counterclockwise.
Speed too small Turn the adjusting bolt clockwise
THROTTLE VALVE
(FULLY OPEN)
THROTTLE
RETURNING SPRING
GOVERNOR SPRING
GOVERNOR ROD
GOVERNOR ARM

3. TROUBLESHOOTING
14
3. TROUBLESHOOTING
3-1 Troubleshooting
3-1-1 Starting Difficult
TROUBLE CAUSE REMEDY
Normal cylinder compression
Normal spark plug spark
Something wrong with the fuel system.
Fuel supply is
not smooth or
no fuel supply.
There is no enough fuel in fuel
tank and fuel cock is closed. Fill fuel, open fuel cock.
Air vent in the fuel filler cap is
clogged Dredge air vent.
Improper or clogged main oil flow
hole.
Readjust or clean, blow
to get through.
Needle valve is not closed properly
or start hole is clogged.
Dismantle needle valve
and repair, clean, blow to
get through.
Float is damaged or sticking. Repair float
Fuel supply is
normal.
Fuel is too filthy or deteriorated Replace
There is water in fuel. Replace
Too much fuel in engine Drain extra fuel, dry up
spark plug electrodes.
Wrong fuel brand
Select proper fuel brand
corresponding with the
requirements.
Normal fuel supply system.
Normal high
–tension line
spark.
Spark plug is in
bad conditions
Too much carbon deposit and dirt
around electrodes. Clear away.
Electrodes are burn damaged
seriously or insulators damaged. Replace spark plug.
Improper electrodes gap. Adjust to proper value.
High-tension line
no spark
Normal spark
plug
High –tension line is damaged. Replace
Ignition coil is damaged. Replace
Magneto loses magnetism. Replace
Abnormal gap between the ignition
coil and flywheel. Adjust gap

3. TROUBLESHOOTING
15
TROUBLE CAUSE REMEDY
Abnormal cylinder compression.
Normal fuel supply system.
Normal spark plug.
Piston ring is worn to or even over its wear
limit Replace
Piston ring is broken. Replace
Piston ring is sticking. Clear up carbon fouling.
Spark plug is not installed tighten or
without a gasket. Tighten with a gasket in.
Air leakage between cylinder block and
cylinder head.
Check cylinder gasket, and the flatness of
the surface by which cylinder block
contacting with cylinder head
Tighten cylinder head bolts in stipulated
order to stipulated torque.
Air leakage in the valves Check valve. Clearance and tightness,
repair if necessary.
If still can’t starting, have the gasoline engine to our authorized dealer for repairing.
SPARK PLUG TESTING
WARNING:
● When testing the spark plug, never hold the high- tension line of the spark plug
with wet hand.
● Make sure there is no spilled fuel outside the engine and that the spark plug isn’t
dipped with fuel.
● To prevent fire, keep sparks far away from the spark plug mounting hole.
Turn the fuel cock to the “OFF” position, and drain the gasoline of the carburetor.
Remove the spark plug and spark plug cap.
Pull the recoil starter grip to drain the gas in the cylinder.
Install the spark plug cap.
Turn the engine switch to the “ON” position.
Pass negative pole (thread) of the spark plug through cylinder cover to connect
grounding and pull the recoil starter grip to observe the spark.

3. TROUBLESHOOTING
16
3-1-2 Power Lack
TROUBLE CAUSE REMEDY
When increasing throttle, speed increase slow or even
decrease and stop running
Ignition system
Fuel supply system
Air in fuel line or fuel line clogged Exhaust air or dredge fuel line
Main oil flow hole is not adjusted properly Readjust
In carburetor, needle valve hole and main
oil flow hole clogged. Clean and blow to get through
Fuel cock is clogged up. Clean, replace damaged part
Too much carbon deposit in combusting
chamber. Clear away
Air cleaner is clogged up. Clean air cleaner filter element
Poor compression
Piston or cylinder or piston ring is worn Replace the worn
Air leakage from the surface by which
cylinder block contacting with cylinder
head.
Replace cylinder gasket
Too big or too small valve clearance. Readjust
Valve tightness is poor. Repair
Compression pressure check
Drain the oil of the fuel tank out.
Drain the gasoline by loosening the oil drain bolt
of the carburetor.
Remove the spark plug cap and spark plug and
install the cylinder pressure meter.
Forcibly pull the recoil starter several times and
measure compression force.

3. TROUBLESHOOTING
17
3-1-3 Speed Unstable
TROUBLE CAUSE REMEDY
Knocking sound
Piston, cylinder or piston ring is worn
excessively. Replace the worn
Piston pin and piston pin hole are worn
excessively. Replace piston or piston pin
Tie rod small head is worn excessively. Replace tie rod
Abnormal
combustion
Gasoline Engine is too hot Shoot trouble
Too much carbon deposit in combustion chamber Clear away
Improper gasoline brand or low gasoline quality Replace with qualified gasoline
Spark lacking
There is water in float chamber Clean
improper spark plug electrodes clearance Adjust
Something wrong with induced coil, and so on Check and replace damaged
parts
3-1-4 Unable Igniting
TROUBLE CAUSE REMEDY
Unable
igniting
Fuel supply
system
Fuel is finished Refill fuel
Carburetor is clogged Check fuel line and dredge
Float is leaking Repair
Needle valve is sticked Dismantle float chamber and
eliminate it
Ignition
system
Spark plug is punctured, or
short-circuited by carbon deposit Replace spark plug
Side electrode of spark plug is dropped
out Replace spark plug
High-tension wire is dropped out Weld on
Ignition coil is punctured or
short-circuited Replace ignition coil
Parking wire is located on engine body Find out meeting and insulate
The other Cylinder is seriously scored and valve
dropped out
Repair or replace damaged
parts

3. TROUBLESHOOTING
18
3-1-5 Gasoline Engine is Overheat
TROUBLE CAUSE REMEDY
Gasoline engine is
overheat
Oil insufficient or wrong oil ratio in the
gasoline Refill engine oil
Exhaust pipe blocked up Clean exhaust pipe
Shroud leaking Repair damaged part
Cooling fins blocked by foreign matter Clear cooling fins
Connection rod deformation to make piston and
cylinder bushing side wear Replace connection rod
Cylinder or piston or piston ring is worn to
make hunting between cylinder and crankcase Replace the worn parts
Improper adjustment of engine governor to
produce speed high. Readjust engine governor
3-1-6 Abnormal Sound
TROUBLE CAUSE REMEDY
Beating sound
Piston, piston ring or cylinder is worn Replace the worn part
Connection rod or piston pin and piston pin hole
are worn Replace the worn part
Crankshaft main neck is worn Replace bearing
Piston ring is broken Replace piston ring
Valve clearance is too big Adjust
Metal beating sound
when abnormal
combustion occurs
Too much carbon deposit in combusting
chamber Clear away carbon deposit
Improper fuel brand Replace fuel
Engine is overheat Find a cause and eliminate it
The other
Improper valve clearance Readjust valve clearance
properly
Fly wheel is not connected with crankshaft
tightly Connect tightly