Why Is My Generator Shaking/Vibrating? [7 Causes And Fixes]

If your generator is wobbling or shaking more than usual, it could be a sign that it needs a thorough inspection to avoid costly repairs down the road.

“Worn-out mounts, loose parts, Improper RPMs, and Stall/low-quality fuel could be the main reasons behind the excessive vibration of the generator and can be fixed without hiring a mechanic”

This article will walk you through the potential causes of the generator’s vibration and how to fix them in an instant.

Why Is My Generator Shaking?

1. Uneven Ground levels or Loose Mounting:

Mounting of a standby generator

Loose mounting or incorrect placement of the generator could also be a leading cause of wobbling/shaking the generator, especially in the case of a standby generator.

A standby generator should be placed on an even surface and mounted by some strong stainless steel bolts for better stability.

NOTE: excessive vibration because of the incorrect mounting could affect the longevity of the generator, for greater stability, make sure to tighten the bolts perfectly so that the generator doesn’t have space to vibrate.

  • Solution: Place the generator on an even surface with proper mounting.

Read the user manual and look for the instructions of the manufacturer regarding the placement and mounting of the generator.

We recommend selecting an even surface with sufficient clearance from the ground; also make sure to mount it with some bolts for greater stability.

2. Worn Out Engine Mounts:

Engine mounts of the generator

Engine mounts are specially designed to hold the engine tightly so that the generator can’t wobble even at a high load.

However, Over time, the mounts of the portable generator become loose or rusty or even broken, and as a result, the generator starts shaking due to the less or no holding force.

  • Solution: Replace or tighten the Mounts.

Inspect the condition of the mounts, if they are loose or damaged make sure to tighten or replace them. Anti-vibration mounts would be ideal if your generator is compatible with them.

3. Non-Uniform/Low RPM:

throttle screw of the generator

RPM (Rotation Per minute) measures how fast the engine is running, if the RPM is Low or unstable the inner parts of the engine like the crankshaft, flywheel, or rotor may vibrate because of the improper combustion cycles.

  • Solution: Use the Tachometer or Hz meter and adjust the throttle screw.
  • Skim the operating manual and look for the manufacturer’s instructions about the ideal RPMs as per the mechanism of the machine you own. Mostly a portable generator’s RPM ranges between 3600 – 3720.
  • Connect a Tacho/Hz meter (frequency meter) to the portable generator and start adjusting the RPMs by turning the throttle adjustment screw. The throttle screw is mostly located above the air filter assembly or the carburetor.

4. Overload:

Over stressing the generator could also cause vibration, if the generator can generate 2500 surge and 2000 rated watts and you are pulling more than that the generator may shake/vibrate.

Also in the worst cases, the generator may overheat, reduce the efficiency, or damage the electrical appliances as well.

  • Solution: Don’t Overload the Machine.
  • Calculate the wattage ratings of each appliance before plugging in
  • Sum up the starting and running wattages of the appliances and compare them with the generator you own, the calculated wattages shouldn’t be more than the capacity.
  • Reset the generator once it is overloaded.

Here is the guide to fixing the overloaded generator.

5. Improper Choke Position:

The purpose of a choke is to control the flow of air to the carburetor, if it’s not at the right position as per the weather conditions, the improper air-to-fuel mixture will be fed to the combustion chamber causing vibration, fluctuated voltages, overheating, etc.

  • Solution: Use the Choke Efficiently.

Use the choke as per the weather conditions, For the initial startup we recommend keeping the choke ON/Close for a quick startup, however after warming up the engine, the choke should be at the Run position to ensure a balanced air and fuel mixture should be fed to the combustion chamber.

Here is the guide about the proper usage of the choke.

6. Misaligned Engine or Parts:

If the generator’s components like the engine, rotor, crankshaft, etc., are not properly aligned, the generator starts shaking doesn’t matter at what RPM it is running.

  • Solution: Aligned the Generator’s components.

Fixing the alignment of the generator isn’t a newbie-friendly task, it needs extensive technical knowledge about the generator’s important organs like shaft, rotor, etc.

If you suspect that the misalignment is the real culprit behind the excessive vibration, make sure to seek help from a professional generator mechanic.

Furthermore, if your generator is still under warranty, consulting customer care would fix the issue without spending a penny.

7. Burnt/Low Oil:

Engine oil is the only lubricant to ensure the moving parts of the engine should work smoothly without excessive friction.

If a generator has burned/low oil, the moving parts could create friction causing vibration, wobbling, noise, overheating, etc.

  • Solution: Monitor the Engine oil.

Read the user manual and look for the manufacturer’s instructions about when and how to change the oil of the generator.

As a general thumb rule the oil of a generator should be changed after 100 to 200 hours of operation or every 6 to 12 months.

Recommended Read: Why Is My Generator Revving Up and Down?

A Few Tips to Prevent Your Generator from Vibration

Schedule Maintenance of the Generator: Clean the fuel lines, carburetor, filters (fuel and air), and spark plug of the generator, also Change the engine oil within the time frame to prevent friction.

Keep an eye on loose Parts Of the generator: If you find loose parts, make sure to tighten the screw/ lugs with an appropriate wrench.

Lubricate the dry parts: Over time the engine belt or other parts like gears, couplings, etc., could be dried and start emitting annoying sounds, make sure to lubricate them.

Use high-quality Fresh fuel: Don’t use stall or low-quality fuel that sits for more than 3 months, the old or low-quality fuel may imbalance the air-to-fuel ratio. 

Place the machine on an even surface: Place the generator on a flat surface with the required clearance for better performance.

Tight the loose mounts or bolts: Make sure to fix the mounts with the help of steel bolts, Also inspect them periodically, if you find them rusted or loosed, replace or tighten them.

Use Anti-vibration mounts: Shock absorbing mounts like M8 Rubber Mounts could be a helping hand to not only dampen the vibrations but also the annoying noise.  

How do I Know if My Generator is Vibrating?

A thorough visual inspection should be done to observe the vibration of the generator; also you can check the speed/RPM of the generator with the help of a tacho/HZ meter to make sure the engine is at the right speed.

Final Words

vibration of a generator isn’t only a great cause of emitting excessive noise but also indicates that the generator should need a thorough inspection to avoid costly repairs down the road.

Mostly a shaking generator can be fixed by doing some basic DIY tasks like tightening the loose parts, adjusting the RPMs, changing the oil, etc.

However, if you suspect a serious cause like misalignment, worn-out mounts, faulty rotor, bad alternator, etc. make sure to seek help from a professional unless your machine still has a warranty.

I hope you are now able to fix a vibrating/shaking generator within no time, if I have missed something please let me know in the comment section, and I will be more than happy to assist you!



Kashif has been a valuable asset to the electric generator industry for over 5 years. Now, As a skilled energy engineer, he’s been on the front lines of diagnosing problems, fixing broken parts, and performing routine maintenance tasks to keep generators running smoothly.

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