RVMP Flex Power 4000i User manual

Read this manual carefully before operation.
This manual includes important guidance for safety operation.
Authorized for installation ONLY in Recreational Vehicles prepped by the RV Manufacturer with fuel lines and a compartment
for permanent generator installs. Do NOT install in any other application without consulting a qualified professional.
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RVMP FLEX POWER
4000i &5500i
INSTALLED GENERATORS
SERVICE MANUAL
®®
®

Introduction 2
Safety Precautions 2
Troubleshoot Issue #1:Generator tries to start, some lights illuminate on the control panel, but generator will not start. 4
Check battery 4
Check oil level 4
Check spark plug circuit for adequate spark 5
Check spark plug for damage 7
Check proper function of fuel module, ECM, and inverter on 4000i 8
Electrical Harnesses 8
Fuel module 8
Engine Control Module (ECM) 8
Inverter 8
No reaction from throttle motor 8
No 120V output 8
Inverter cooling fan does not spin 9
Green READY light never comes on 9
Check proper function of fuel module, starter, and inverter on 5500i 9
Electrical Harnesses 9
Fuel module 9
Starter 9
Inverter 10
Pull start test 10
No reaction from throttle motor 10
No 120V output 10
Inverter cooling fan does not spin 10
Green READY light never comes on 10
Check for restrictions to gasoline line 10
Check for vacuum lock in the gasoline line 11
Check housing temperature sensor disc 11
Check gasoline solenoid on carburetor 12
Check alternate fuel source 12
Check fuel pump 13
Check fuel selection switch 13
Troubleshoot Issue #2:Generator starts sometimes, but will not start other times (intermittent starting). 13
Check battery 13
Check oil level 13
Check electrical grounds 14

Battery ground cable connection 14
Ground posts 14
Grounding jumper wire for mounting rack 16
Troubleshoot Issue #3:Generator completely dead, does not attempt to start and no lights illuminate on control panel. 17
Check battery 17
Check fuses 18
Small fuel module fuse 18
Larger inverter fuse for 4000i 18
Larger inverter fuse for 5500i 18
Troubleshoot Issue #4: Generator starts but runs rough when the breaker is OFF with no electrical load on the generator.
18
Check throttle for proper operation 18
Inspect wire harnesses 18
Check for a bad stepper motor 18
Check for bad inverter 19
Check needle jet for dirt or obstructions 20
Check proper setting on altitude adjustment 22
Clean old gas or buildup from carburetor 23
Drain old gasoline 23
Run with LP 23
Clean carb with Sea Foam 23
Air filter inspection and cleaning 23
Check for gasoline vaporization conditions 24
Check for proper LP regulator pressure 24
Check for low LP 24
Troubleshoot Issue #5: Generator starts but only runs for a few minutes, then shuts down. 24
Check for proper ventilation 24
Check for gasoline vaporization conditions 26
Check for proper LP regulator pressure 26
Check for restrictions to gasoline line 26
Check for vacuum lock in the gasoline line 27
Troubleshoot Issue #6: Generator starts and runs but there’s no power output. 27
Check for electrical overload 27
Check for bad inverter 27
Instructions for replacing fuel pump 28
Instructions for replacing the fuel filter 33
Instructions for replacing the carburetor 35
1

RVMP®Flex Power®Generators
Troubleshoot and Service Manual
Introduction
This is the troubleshoot and service manual for FLEX POWER generator models 4000i and 5500i. While these models share
many similarities, note several sections of this manual where the technical differences between the models are explained in
detail.
Safety Precautions
Read and understand all instructions before installing or operating on this product. Adhere to all safety labels. This manual
provides general instructions. Many variables can change the circumstances of the instructions, i.e., the degree of difficulty,
existing equipment, operation and ability of the individual performing the instructions. Failure to correctly follow the provided
instructions may result in death, serious personal injury, severe product and/or property damage and may void portions of
the warranty (See Owner’s Manual for warranty info). We recommend that installation and servicing is performed by a
qualified and experienced RV technician.
This manual cannot provide instructions for every possible scenario, but provides the general instructions, as necessary, for
troubleshooting and servicing the generator in most situations. If you have any questions, please contact us at:
RV Mobile Power, LLC
Phone: (855) HAPPYRV
Email: [e-mail]
www.rvmp.co
FIRE SAFETY NOTICE
Keep multi-class ABC fire extinguishers handy. Class A fires involve ordinary combustible materials such as wood and cloth.
Class B fires involve combustible and flammable liquid fuels and gaseous fuels. Class C fires involve live electrical equipment.
WARNING
The "WARNING" symbol above is a sign that a procedure has a safety risk involved and may cause death or serious personal
injury if not performed safely and within the parameters set forth in this manual.
●Failure to follow instructions provided in this manual may result in death, serious personal injury
and/or severe product and property damage, including voiding all or portions of the warranty.
2

●Do not operate equipment when mentally or physically fatigued or after consuming alcohol or
drugs.
●Do not use starting fluids which can cause an explosion and may result in death, serious personal
injury and/or severe product and property damage. Do not use evaporative starting fluids. They
are highly explosive.
●Installing or maintaining a generator can cause severe personal injury. Wear personal protective
equipment including safety glasses, hard hats, steel-toed shoes and protective clothing when
working on equipment.
●Benzene, found in some fuels, and used engine oils have been identified by some state and
federal authorities to cause cancer or reproductive toxicity. Do not ingest, breathe fumes or come
into contact with gas or oil when checking, draining or adding gas and oil.
●Hot, moving and electrically-live parts can result in death, serious personal injury and/or severe
product and property damage. Only trained and experienced personnel should make adjustments
while the generator is running. Otherwise, adjustments should be made only when the generator is
not running.
●Moving parts can catch on loose clothing items or jewelry. Do not wear loose clothing or jewelry
near moving parts including shafts, fans, belts and pulleys.
●Moving parts can seriously injure body appendages, including fingers. Keep hands away from
moving parts. Keep protective guards in place over fans, belts, pulleys and other moving parts.
●Improperly installed electrical connections may result in death, serious personal injury and/ or
severe product and property damage. Electrical connections must be made by trained and
experienced electricians in accordance with applicable codes.
●Back-feeding to shore power may result in death, serious personal injury and/or severe product
and property damage. The generator must not be connected to shorepower or any other source of
electrical power. An approved switching device must be used to prevent interconnections and
serious damage to the generator.
●Operating, servicing and maintaining and maintaining this equipment can expose you to
chemicals, including engine exhaust, carbon monoxide, phthalates and lead, which are known to
the State of California to cause cancer and birth defects or other reproductive harm. To minimize
exposure, avoid breathing exhaust, do not idle the engine except as necessary, service your
equipment in a well-ventilated area and wear gloves or wash your hands.
●Do not install the generator on a watercraft or boat. Such an installation might violate U.S. Coast
Guard regulations and may lead to damage, fire, injury, or death.
3

CAUTION
The "CAUTION" symbol above is a sign that a procedure has a safety risk involved and may cause personal injury, product or
property damage if not performed safely and within parameters set forth in this manual.
●Always wear eye protection when performing service, maintenance or installation procedures.
Other safety equipment to consider would be hearing protection, gloves and possibly a full face
shield, depending on the nature of the task.
Troubleshoot Issue #1:Generator tries to start, some lights illuminate on the
control panel, but generator will not start.
Check battery
Check the battery for at least 12-13V DC. Use a multimeter to determine the battery voltage by applying the
probes to the positive and negative terminals on either the battery itself or the terminals on the side of the generator
which accept the positive and negative battery cables.
Check the battery for at least 450 CCA. For lead acid batteries, use a battery tester to measure the cold
cranking amps (CCA) of the battery and ensure at least 450 CCA. For lithium batteries, ensure that the battery has a
state of charge (SOC) of at least 25%.
Check oil level
The generator is equipped with an oil level sensor that prevents the generator from starting when the oil level is
too low. There is a Low Oil light on the front control panel that will illuminate when the sensor measures an oil level that
is below the threshold for starting. Generally speaking, the generator oil capacity must be almost completely filled in
order for this switch to actuate and allow the generator to start. The sensor for the oil level is very sensitive and so even
having slightly too little oil will prevent the generator from starting.
If the Low Oil light is illuminating, this indicates that the low oil float is sending spark energy to the light.
If the Low Oil light is not illuminating, it is possible the spark circuit is not producing adequate power. Check
the spark circuit for adequate power.
If the Low Oil light is illuminated but the generator is full of oil, there could be an issue with the float switch in
the oil sensor. Try unplugging the oil sensor and see if the generator starts. You can unplug the wire harness for the oil
sensor in order to temporarily disconnect this sensor, but make certain that the generator is full of oil before trying this
and NEVER operate the generator without having the oil sensor plugged in and operating, this is only for a quick test. If
the generator starts, then there is likely a problem with the float in the sensor and it may need replaced. If it doesn’t
start, proceed to check the other problems.
If the oil reservoir is full but you know there is not enough oil in the unit, there is likely an air bubble inside the
oil pan and/or crank case. To remove the bubble, pull the manual start or try to start the unit from the start button (it
may take several pulls or attempts to start in order to completely remove the air).
4

Check spark plug circuit for adequate spark
Remove spark plug boot and unscrew spark plug from the engine with a spark plug socket. Re-attach the spark
plug boot and carefully observe the spark plug gap while trying to start the generator. Be sure to stay clear of the spark
plug gap and only observe for a spark with the naked eye. Depending on the amount of ambient light, the spark may not
be observable and this does not necessarily mean there is a bad spark plug.
If a spark cannot be observed with the naked eye, use an inline spark tester to determine if there is adequate
spark from the spark circuit. Place the in-line tester in between the boot and the spark plug and attempt to start the
generator. When using an inline tester it should be easy to determine the amount of light being generated by the tester
and this indicates the strength of the spark circuit burst.
If the inline spark tester indicates only a small amount of light when attempting to start the generator,
re-check the voltage on the battery and make sure that it’s not too low. Also check the ignition coil for proper
resistance as described above.
If the inline spark tester indicates a proper amount of light when attempting to start the generator, then
the spark plug circuit for the generator is working properly.
If there is no light observed within the inline spark tester, then there is a problem with the spark circuit,
likely the ignition coil.
To check an ignition coil for proper function, check the following two resistances with a digital multimeter
placed on the resistance setting (Ω):
1. Main ignition coil harness. Place one multimeter probe on the first conductor inside the
harness and the other multimeter probe on the second conductor and measure this resistance.
This measurement should be around 1-2 ohms. If the resistance is infinite, there is an open
circuit failure and the ignition coil needs to be replaced.
5

6

2. Output spark plug wire. Place one multimeter probe on the first conductor inside the harness
and the other multimeter probe on the interior conductor of the spark plug boot. This
measurement should be around 15,000 ohms. If the resistance is infinite, there is an open
circuit failure and the ignition coil needs to be replaced.
Check spark plug for damage
If the generator is new, it’s very unlikely that the spark plug would be bad and therefore prevent the generator
from starting. However, in some situations even a new spark plug could be fouled by too much fuel during the initial
startup, perhaps by holding the Prime button down for too long before attempting to start the generator. If this
happens you should smell fuel, but perhaps not in all cases. To overcome this situation, simply allow the fuel to dry off
the spark plug and then attempt to restart after about ten minutes.
If the generator has been used previously, it’s possible that the spark plug has gone bad, especially if the
generator was used in less than ideal conditions. For example, if the air filter is clogged the balance of fuel to air in the
carburetor will not be in balance and fuel deposits will be left on the spark plug.
●Normal Wear: The electrode and insulator should have a tan or light brown color, indicating the plug is
functioning well.
●Fouling: Look for deposits like oil, fuel, or carbon buildup on the electrode. Fouling can hinder the spark plug's
performance.
●Wear and Tear: Examine for any cracks, chips, or other visible damage.
●Serious Corrosion: Examine the threads of the spark plug and the electrode for corrosion.
Replace the spark plug if there are noticeable signs of fouling, wear and tear, or corrosion.
Proper spark plug gap: 0.024 in - 0.0315 in (0.60 mm - 0.80 mm)
7

Check proper function of fuel module, ECM, and inverter on 4000i
Electrical Harnesses
The 4000i requires electrical communication between the various components such as the fuel module, ECM,
and the inverter in order to start and run properly. In some instances, it's possible that one of the electrical harnesses
came unplugged through vibration or snagging when the cover was attached/replaced. If the generator is not starting
or running properly be sure to check all wire harnesses.
Fuel module
During normal operations, when the start button is pressed there should be audible indications from the fuel
pump or fuel solenoid of proper starting operations. When the fuel selection switch is on gas, you should hear the fuel
pump running as part of the startup sequence. When the fuel selection switch is on LP, you should hear the gas
solenoid module click. If you hear nothing when the start button is pressed, check the 10 Amp fuse to the fuel module
(located near the front control panel) as this may be blown and if so this is preventing the fuel module from getting
power and operating the fuel pump/fuel solenoid properly.
Engine Control Module (ECM)
The 4000i model does not use a traditional starter, but instead uses the windings inside the stator/rotor of the
generator to create a spark. When pressing the start button, If you can hear the fuel pump running or the fuel solenoid
‘click’ but there is no spin or attempt to spin the rotor in the generator then it’s possible that the ECM could be bad. To
test for this, try using the manual pull start to start the generator. If the generator starts with the pull start but will not
start with the start button, then the ECM is likely bad. Replace the ECM to confirm.
Inverter
Generally speaking, if the inverter had a failure the unit should still be able to start and run (although rough).
So if a 4000i generator is failing to start it's not likely due to a bad inverter.
No reaction from throttle motor
However, if there is NO reaction from the throttle motor once the generator starts, it is possible that the
inverter could be bad because during proper operation the inverter supplies the throttle motor with instructions on
when to increase/decrease the throttle due to electrical load(s) on the generator. Thus, during proper operations, the
throttle motor should be making adjustments during idle and also once an electrical load is applied. If the inverter fails
to send proper instructions to the throttle motor, the RPM of the motor would stay constant regardless of whether there
is any type of electrical load on the generator or not. If this scenario is present, try swapping out the throttle motor for a
motor that is known to be working. If the throttle motor still does not move with a working replacement, then it's likely
that the inverter is bad and needs replaced.
No 120V output
Additionally, there could be a failure in the inverter if the generator starts but there is no 120V output. You can
observe this failure by looking at the digital display on the front of the unit once the generator starts and pressing the
option button on the display until the output voltage is displayed. If zero volts is indicated on the display for the output
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