Read the manual thoroughly and understand all of the instructions, cautions, and warnings before using this equipment. If any section of the manual is not understood, contact your nearest authorized dealer, or contact Generac Customer Service at 1-888-436-3722 (1-888-GENERAC), or www.generac.com with any questions or concerns. 

 

Inspecting and cleaning my portable generator's air filter 

A well-maintained air filter allows for the necessary airflow for proper functioning of your portable generator. Inspection/cleaning of the air filter should be done routinely. This article covers how to determine if your air filter requires cleaning, when to clean or replace, steps for cleaning, and signs of a dirty filter. 

 

Environment 

This article applies to most portable generators. 

 

When to inspect your portable generator's air filter

• Inspection of your air filter is part of the routine maintenance outline in the maintenance schedule of your owner's manual. 
• The air filter should be inspected every year or according to the maintenance run hours interval - whichever occurs first. 
• More frequent inspection is required under dirty and dusty operational conditions.

 

Signs of a dirty air filter 

If the air filter is dirty, your generator may exhibit: 

• Running or idling rough
• Black smoke from the exhaust
• High fuel consumption 

 

How to determine if the air filter needs cleaning or replacement

• Dirt and dust buildup - A light coating of dust is normal and can be cleaned, but a thick layer indicates the need for thorough cleaning or even replacement. 
• Oil or grease - Oily residue can often be cleaned, but if the filter is heavily soaked, consider replacing it. 
• Tears or damage - any physical damage to the air filter means it must be replaced, as it will no longer be able to effectively protect the engine. 

 

Before cleaning the air filter

Always ensure the generator is OFF, COOLED DOWN, and DISCONNECTED from any loads before proceeding. 

 

Steps for cleaning the air filter

This section provides a general overview of common air filter configurations and steps to clean them. Always refer to the owner's manual for your specific model for precise instructions, as configurations may vary. 

 

Note: The following are examples of common air filter configurations and steps and are not meant to be an exhaustive list. 

 

 

GP6500 - GP8000

1. See Figure 4-3. Turn knob (A) and remove the air filter cover. 
2. Wash in soap water. Squeeze the filter dry with a clean cloth and allow it to dry. (DO NOT TWIST)
3. Clean the air filter cover before re-installing it. 

 

 

 

GP15500 - GP18000

1. Release latches (A) and remove air filter cover (B).
2. Remove filter (C). Gently tap the filter on a solid surface. 
3. Clean air filter cover before installation. 

 

 

 

 

GP3300i -  iQ3500

1. Unscrew bolt (A) and remove the air filter cover. 
2. Wash filter (B) in soapy water. Squeeze dry in a clean cloth (DO NOT TWIST). 
3. Clean air filter cover before installation. 
4. Replace the side cover and screws. 

 

 

Air filter FAQs

Can I use any air filter replacement? How do I find the part number of my air filter?

• Always use the air filter part number indicated in your owner's manual. 
• Where can I download a user manual for my Generac portable generator?

 

Where can I buy a replacement air filter? 

• Replacement air filters can be purchased through Generac Independent Authorized Service Dealers (IASD) and online through Generac's Online Parts Store. 

 

What happens if I don't clean the air filter?

• A neglected air filter can lead to poor generator performance and may damage the engine if run with a dirty air filter.
• Service air filters more frequently in dirty or dusty conditions. 

 

Why is there oil in my air filter?

Oil in the air filter may occur for several reasons but are typically related to the following maintenance issues or improper operation:

• Tipping or tilting the generator - If the generator is tilted or tipped, oil from the crankcase may flow back into the air filter. 
• Overfilling the oil - When the crankcase is overfilled, it can cause increased pressure, which can force oil back into the air filter. 
• Dirty or clogged air filter—If the air filter is already dirty, oil vapor can be forced back into the housing due to an excess of pressure caused by improper ventilation.