Description

The Comet MC25GR is a professional-grade, medium-pressure diaphragm pump designed for durability and versatility. The “GR” designation indicates that this model comes equipped with a factory-installed gearbox, allowing it to be bolted directly to a gasoline engine with a 3/4″ straight keyed shaft (such as a Honda GX120 or GX160).

It is a “top-tier” choice for small-to-medium mobile spray rigs where reliability is more important than the cheapest price point.

Key Features & Performance

• Two-Diaphragm Design: Provides a consistent, smooth flow with minimal pulsation, which protects your hoses and spray guns from wear.

• Anodized Aluminum Construction: The pump bodies are treated to resist corrosion from common agricultural chemicals and fertilizers.

• Direct Drive Gearbox: Eliminates the maintenance headaches of belts and pulleys. The gearbox reduces engine RPM to the pump’s optimal operating speed.

• Self-Priming: Capable of pulling fluid from a tank even when the pump is mounted above the water line.

Technical Specifications

Common Applications

• Pest Control: Perfect for perimeter spraying and reaching second-story eaves.

• Lawn Care: Ideal for liquid fertilization and herbicide application on residential and commercial turf.

• De-Icing: Used for spraying liquid brine on sidewalks and entryways.

• Greenhouse Spraying: Compact enough for small carts while providing enough pressure for fine misting.

Maintenance & Parts (6084.0080.00)

To keep the MC25GR running at peak performance, pay attention to these three areas:

1. Oil: The pump uses 30W Non-Detergent Oil. Always check the sight glass before operation. If the oil looks “milky,” stop immediately—this means a diaphragm has ruptured.

2. Pressure Regulation: This pump requires a pressure regulator (typically the Comet 1804.0005.00 or similar) to set your desired PSI and return excess fluid to the tank.

3. Winterization: Because the heads are aluminum, they can crack if water freezes inside. Always flush with RV antifreeze if storing in cold temperatures.

Need a Repair? If you are looking for the rebuild kit for this specific pump, you will typically look for the Comet 5026.0080.00 kit, which includes the diaphragms and check valves.