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Complete Guide to Caterpillar RP7500E Portable Generator

Table of Contents

Table of Contents


Caterpillar RP7500E is a robust, high-quality generator with a long list of premium.

The generator is built to be very user-friendly with electric starter powered by a self-charging Lithium Ion starter battery with easy pull-cord option as a backup.

Listed below are all RP models are:

  • RP3500 – 3500 w (continuous)
  • RP5500 – 5500 w (continuous) / 6875 w (starting)
  • RP6500E – 8125 w (starting) / electric start
  • RP7500W – 7925 w (continuous) / 9375 w (starting) / electric start
  • RP12000E – 12000/11000 watts (running) / 15000w (starting) / electric start

All models come with a wide-mouth fill cap located on top of the metal fuel tank.

As a nice touch, the fuel tank has depression channels to keep fuel spills to a minimum.

Electric start models come with a heavy-duty Lithium Ion battery that will hold the charge up to a year so the generator is ready when you need it.

The will also self-recharge when the generator is running (if your battery is completely dead, simple remove and charge using a battery charger like this Schumacher 30 Amp 12V Fully Automatic Smart Battery Wall Plug-In Charger

Unfortunately, Caterpillar stopped making all portable generators in 2020 (except one inverter model) so the replacement parts can be hard to find so I will do my best to show you available sources.

However, as of 2022, I still own and use RP7500E generator for my home emergency power needs (had zero issues since 2017).

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Where to Buy

As stated previously, CAT RP7500E portable generator has been discontinued by Caterpillar back in 2020.

There are still few vendors selling various RP-series generators. If you purchase one of these units, I highly recommend that you check the following:

  • Make sure there is engine oil
  • Remove the spark plug and squirt about 2 tablespoonful of oil into the cylinder head
  • Change oil after 1 hours of operation

Extension Cords or Wire to the Main Electric Panel?

Although CAT RP7500E genny has more than enough outlets, you cannot power larger appliances like a furnace as well as small appliances (i.e. dishwasher).

Instead, I use a gen cord from my generator shed (you can either buy something like this or build a relatively inexpensive generator shed (see how I built one in this post) to my main electric panel to power the house.

Although my Caterpillar RP7500W generator is a powerful unit, I cannot cannot power the entire house so I selectively switch on and off my circuit breakers to manage the load.

If you want to see my setup generator-to-main-panel setup, please read my post Connecting a Portable Generator to the Home Main Electric Panel (Part 1 is here)

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What Comes in the Box

  • RP7500E unit + assembled frame
  • Handlebar
  • Oil
  • Funnel
  • Screwdriver
  • Tires
  • Multi-Connector Power Cord, 25 ft (item# 502-3692)

Dimensions and Weights

Height24.7 in / 628 mm
Width27.4 in / 696 mm
Length32.9 in / 835 mm
Extended Length45.2 in / 1148 mm
Unit Weight (Dry)207 lbs / 94 kg
Height23.2 in / 590 mm
Width22.6 in / 575 mm
Length34.4 in / 875 mm
Shipping Weight219 lbs / 99 kg

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Technical Specs – Engine

Produce SeriesRP Generators
Engine Displacement420 cc, 4-Stroke, Forced Air Cooling
Engine TypeOver-Head Valve (OHV), single cylinder
Engine RPM3600
Fuel GaugeOn Tank
Fuel Tank Capacity (nominal)7.9 gallon / 30 liters
Fuel Tank MaterialMetal
Fuel TypeUnleaded Gasoline >= 87 Octane**
Idle ControlNone
Low-Oil Shutdown MethodLow Level
Lubrication MethodSplash (not pressurized)
Oil Capacity1.1 qt / 1 L
Oil, RecommendedSAE30 or 10W-30
Run Time at 50%11 Hours
Run Time at 100%7.5 Hours
Starting MethodElectric or Pull

** No more than 10% ethanol; fuel stabilizer should be used when storing gasoline

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Technical Specs – Electrical

Produce SeriesRP Generators
AC Rated Output Running Watts7500 watts
AC Maximum Output Motor Starting Watts9375 watts
AC Voltage Output120V / 240V
AC Frequency60 Hz
DC Output
Ignition SystemTransistorized Magneto
Total Harmonic Distortion (THD) (4)
Voltage RegulationAutomatic Voltage Regulation (AVR)
Low-Oil Shutdown MethodLow Level
Battery TypeSelf-Charging Lithium Ion
Battery rated capacity (AH)1.6
Receptacle 1 and 25-20R, GFCI, 20A
Receptacle 3NEMA L5-30R, twist-lock, 30A, 120V
Receptacle 4NEMA L14-30R, twist-lock, 30A, 120V / 240V

(4) All electric power generated from portable and standby generators can produce “harmonic distortion” which can damage sensitive electronic devices. The Total Harmonic Distortion or THD, number is calculated by adding up all harmonics in order, squaring them, the finally taking the square root of that total divided by the fundamental. THD is usually expressed in percentages. The lower this number (usually 5-6% or lower is best), indicates “cleaner” power to sensitive electronics.

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Technical Specs – Extra Features

Produce SeriesRP Generators
Illuminated Control PanelYes, LED light
Handle StylePadded, Double Hinged
Wheel TypeNever-flat
Indicator Lights
Warranty2-year Limited, extended to 3-year when registered within 30 days

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Display Codes

  • P50 – It is a reminder to change the oil and check the spark arrestor after 50 hours of use.

Troubleshooting Your RP7500 Portable Generator

Maintenance and Care

Air Filter – comes with an easy access door for air filter cleaning

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Replacement Parts

Due to RP7500E model being discontinued back in 2020, Caterpillar OEM parts are rather hard to find.

At this time, this eBay page is the best source of available RP7500E replacement parts

  • Large Protective Cover (item # 502-3706)
  • Service Kit for RP6500E/7500E (item # 502-3704) – oil, air filter and a spark plug
  • Multi-Connector Power Cord, 25 ft (item# 502-3692)
  • Spark plug – Part #
  • Air Filter – Part #
  • Engine Oil – SAE30, 10W-30

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Frequently Asked Questions

  • Who makes the engine used in Caterpillar RP75000E?
    • According to Caterpillar, it produces its own engine but I think the engine may be produced by DuroMax

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