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Review of the Generac 7678 GP3600 Open Frame Portable Generator

4500 Starting Watts, 3600 Running Watts on Gasoline

Electric Start: No

Weight: 105lbs

Noise: 0dB


Should You Buy It?

This is an attractively priced generator that is recommended by the people who have bought it. It's not too heavy and can be moved from place to place quite easily. Although it has no electric start, the power outputs are reasonable for a variety of applications, so it's also a good option for keeping essential appliances going during outages. 

If your power needs match what this portable generator can provide, and you like its price, then yes this would be a good buy. But if your neighborhood experiences frequent and longer outages, you may want to look at something quite a bit bigger, like the Westinghouse WGen7500. This is especially so where the weather requires you to use heating or air conditioning.

Key Points about the Generac 7678 GP3600

Easy assembly
Hour gauge
Petrol gauge
Economical operation
Open frame so noisier
Not for use with sensitive electronics
No electric start
Solid no-flat wheels

Overview of the Generator


The Generac GP3600 is an open frame generator that can provide you with backup power for multiple appliances in emergency situations. It's also used by owners as a power source for their RVs, taking on camping trips, and working with power tools away from an electricity supply.

Control and Features

Generac-7678-GP3600 Control Panel

The unit comes with the usual features found on other comparable generators. It has a low oil shutdown system, which automatically stops the engine if the level falls too low. It doesn't use inverter technology so it's unsuitable for use with sensitive electronics without a line cleaner/surge protector.

A useful hour meter allows you to keep track of when it's time for a maintenance stop. There's a relatively large fuel tank, and you can monitor the gas level via the fuel gauge.

There is no electric start on this model, just a manual recoil cord.

The GP3600 has 2x120v duplex 20Amp receptacles for household use, and a single 120v 30Amp outlet primarily for RV use. All of the outlets have circuit breakers and are protected from the elements when not in use by rubber covers.

Detailed information for this model is contained in the Generac GP3600 manual.

As the generator does not have a carbon monoxide (CO) sensor, only use it outside and be alert to the danger of toxic fumes being blown into the home. And consider a cover to keep it safe from the elements both when it's in use and in store. One such cover is the GenTent Universal Running Cover.

Power Output

A Generac OHV 212cc splash lubrication gasoline engine produces 4500 starting watts and 3600 running watts. It has a feature called PowerRush™ Advanced Technology, which Generac say allows the generator to deliver 40% more starting power. There is no Eco mode and the engine spins at a constant 3600 RPM. On a full tank of gas (3.7 gal.) it runs for 9.3 hours with a 50% load.

Overhead Valve Technology (OHV) is a system where the intake and exhaust valves are located above the cylinder in a separate component of the engine called the head. This is generally thought to be of better quality than engines which have the valves in the block, and provide benefits of better combustion, reduced fuel and oil consumption, and longer engine life.

This is not an inverter so you will lead a UPS/line cleaner/surge protector when connecting any sensitive electronic equipment.

When choosing a portable generator, be sure to take into account where you live. This is because altitude and ambient temperature can significantly affect the performance and output any generator is capable of producing at sea level. We have put together some information on this important subject. Be sure to take a look.


At 105lb it's not too hard to move around. It has solid rear wheels and a foldable handle. While solid wheels never go flat, they can develop flat spots when the unit is stored for long periods. So the advice is to move it regularly to prevent any deformations. Alternatively, you can take the weight off the wheels by jacking up the generator when putting it into store.

Noise Level

Generac don't publish noise levels for any of their generators as there are no standards to make fair comparisons.

What Most Buyers Like

Given how many generators Generac sell across their range it's surprising that there aren't more reviews of the GP3600. Those who have reviewed the generator, however, recommend it as an above average and affordable unit. They comment positively over its ease of assembly and use. For example, it does very well running a refrigerator, freezer, house fans, TV, and lamps.

The unit is also small enough to be taken on a camping trip or run some power tools away from the grid. 

What Some Buyers Like Less

Several owners say it's noisy, but not too loud, and compares with other similar generators. It's an inconvenience worth paying for the savings made in the purchase price. And one owner claims the company does not stand by its warranty. We think this might be more of a question of not knowing what the warranty covers.

AC Rated Output Running Watts3600
AC Maximum Output Starting Watts4500
Rated AC Voltage120 VAC
Rated AC Frequency 60 Hz
Rated 120 VAC Amperage 30A
Engine Displacement 212cc
Engine TypeOHV
Engine RPM Oil3600
Recommended Oil 10W-30 / SAE 30
Capacity qt (L) 0.63 (0.6)
Lubrication MethodSplash
Automatic Voltage Regulation (AVR) Yes
Choke LocationOn Engine
Fuel Shut Off Starting Method On Fuel Tank
Starting MethodRecoil Pull Start
Low Oil ShutdownYes
Neutral Floating Yes
Floating Neutral Yes
Start Switch Type On/Off
Start Switch Location On Control Panel
Fuel GaugeYes
Fuel Tank Capacity gal (L) 3.7 (14)
Run Time at 50% (Hours) 9.3
Handle StyleSingle Folding
Wheel Type 8” Never Flat
Warranty- Residential3 Year Limited
Warranty- Commercial1 Year Limited
IncludedEngine oil, oil funnel
Handle and wheel kit
Owner manual
Length in (mm) 24 (610)
Width in (mm) 22.5 (570.5)
Height in (mm)21.3 (541.5)
Extended Length in (mm) 36.5 (924)
Carton Length in (mm) 27.2 (690)
Carton Width in (mm) 17.9 (455)
Carton Height in (mm) 19.7 (500)
Unit Weight lbs (kg) 105 (47.6)
Shipping Weight lbs (kg)112 (50.8)