AIR GREEN MP-791 Gravity Feed Air Spray Gun Instruction Manual

1. Product Overview

The AIR GREEN MP-791 is a high-performance gravity feed air spray gun designed for precise and efficient paint application. Utilizing High Volume Low Pressure (HVLP) atomization technology, it ensures a fine spray effect, optimal quality, and paint efficiency, potentially saving 10-30% paint compared to conventional spray guns.

The AIR GREEN MP-791 Spray Gun, featuring a 1.3mm nozzle for atomized fine spray.

2. Components and Controls

Familiarize yourself with the main components and adjustment controls of your MP-791 spray gun:

Diagram illustrating the key components and controls of the MP-791 spray gun.

• Nozzle: Controls the spray pattern and atomization. The MP-791 features a 1.3mm nozzle.
• Flow Regulation Knob: Adjusts the paint output. Loosening increases paint output, while tightening decreases it.
• Air Pressure Adjustment Knob: Controls the air pressure for atomization.
• Trigger: Features a two-gear design for versatile operation.
• Air Adjust Knob: Fine-tunes the air flow.
• Air Inlet: Connects to your air compressor (1/4'' connection).
• Cup: 600 CC capacity for gravity feed paint supply.

The MP-791 Spray Gun comes with essential accessories for setup and maintenance.

3. Setup

1. Connect Air Supply: Attach your air compressor hose to the 1/4'' air inlet at the bottom of the gun handle. Ensure a secure connection.
2. Fill Paint Cup: Pour your prepared paint into the 600 CC gravity feed cup. Ensure the paint is properly thinned according to the paint manufacturer's recommendations for spray application.
3. Adjust Air Pressure: Set your air compressor to the recommended working pressure of 2.5 bar (36 psi). Fine-tune using the air pressure adjustment knob on the gun.
4. Adjust Fluid Flow: Turn the Flow Regulation Knob to control the amount of paint released. Start with a moderate setting and adjust as needed.
5. Adjust Atomization/Fan Pattern: The 360° adjustable nozzle allows you to control the spray pattern. Rotate the air cap to achieve the desired horizontal or vertical fan pattern.

The 360° adjustable nozzle ensures a flat and even paint surface.

4. Operating Instructions

The MP-791 features an intimate trigger design with two gears for enhanced control:

• First Gear: Lightly pull the trigger to activate the first gear, which blows air to clear dust from the product surface before painting.
• Second Gear: Pull the trigger further to engage the second gear, which releases paint. This allows for light, flexible, and efficient work without tiring.

The Quick Trigger offers two distinct gears for dust removal and paint application.

Spraying Technique:

• Maintain a spraying distance of 17-23 cm from the surface.
• The large-width fan spraying capability provides good coating uniformity and fine atomization, resulting in accurate color matching and a perfect surface finish. The pattern width can range from 2 cm to 27 cm depending on adjustments.

Illustration of the large-width fan spraying, showing optimal distance and pattern.

Paint Adjustment Button:

The alloy adjusting knob is strong, durable, and provides precise adjustment to maintain spraying consistency.

• Flow Regulation: Loosening the knob increases paint output; tightening decreases it.
• Atomization Adjustment: Loosening allows for a large range of spray paint, while tightening results in a smaller range, adjustable according to product size.

Detailed view of the paint adjustment button for flow and atomization control.

Video Demonstration:

A short video demonstrating the atomization and spray pattern of the MP-791 spray gun.

5. Maintenance

Proper maintenance ensures the longevity and optimal performance of your spray gun.

1. Cleaning After Each Use: Immediately after use, empty any remaining paint from the cup. Pour a small amount of appropriate cleaning solvent into the cup and spray it through the gun until clear.
2. Disassembly and Detailed Cleaning: For thorough cleaning, disassemble the air cap, nozzle, and needle. Use the provided cleaning brush and solvent to remove all paint residue from these components. Pay special attention to the pure copper air cap and stainless steel needle tip, which are crucial for fine atomization and durability.


The pure copper air cap ensures high atomization and uniform spray.



The stainless steel needle tip is wear-resistant and provides a long service life.

3. Lubrication: Apply a small amount of spray gun lubricant to moving parts such as the trigger pivot and needle packing after cleaning.
4. Storage: Store the clean and dry spray gun in a safe place, away from dust and extreme temperatures.

6. Troubleshooting

Here are some common issues and their potential solutions:

• Uneven Spray Pattern:
  • Check for clogged air cap holes or nozzle. Clean thoroughly.
  • Ensure consistent air pressure.
  • Verify paint viscosity is correct.
• Poor Atomization (paint spitting or coarse spray):
  • Increase air pressure slightly.
  • Check for blockages in the air cap or nozzle.
  • Ensure paint is properly thinned.
• Paint Leaking from Nozzle:
  • Check if the needle packing nut is too loose.
  • Inspect the needle and nozzle for damage or wear.
  • Ensure the needle is fully seated when the trigger is released.
• No Paint Flow:
  • Check if the fluid needle is stuck or blocked.
  • Ensure the paint cup is not empty and the vent hole is clear.
  • Verify the fluid adjustment knob is not fully tightened.

7. Specifications

Official product parameter table.

8. User Tips

• Always wear appropriate personal protective equipment (PPE), including a respirator, safety glasses, and gloves, when operating the spray gun.
• Practice on scrap material to get a feel for the spray pattern and adjustments before working on your final project.
• Ensure proper ventilation in your work area to prevent the buildup of fumes.
• Clean the spray gun immediately after each use to prevent paint from drying and clogging the internal components.
• Regularly check all connections for leaks to maintain consistent air pressure and prevent paint drips.

9. Warranty and Support

For any questions, technical assistance, or warranty claims, please contact the seller or manufacturer directly. Keep your purchase records for reference.