King Kutter RFM-72-YK Rear Discharge Finish Mower: Efficient & Durable Mowing for Large Areas

Imagine this: You’re standing at the edge of your sprawling property, the morning sun glinting off acres of overgrown grass. It’s a beautiful sight, but also a daunting one. The task of mowing it all seems almost Herculean. You could spend days wrestling with a smaller mower, battling uneven terrain and endless rows of clippings. Or, you could harness the power and precision of a machine designed specifically for the job: the King Kutter RFM-72-YK Rear Discharge Finish Mower.

The evolution of lawn care has mirrored humanity’s pursuit of efficiency. From the hand scythes of centuries past to the first rudimentary mechanical mowers, the goal has always been the same: to tame nature’s wild growth and create orderly, aesthetically pleasing landscapes. Today, tractor-powered finish mowers like the King Kutter RFM-72-YK represent a significant leap forward, combining power, precision, and durability to tackle even the most challenging mowing tasks.

Introducing the King Kutter RFM-72-YK: A Closer Look

The RFM-72-YK isn’t your average lawn mower. It’s a robust, tractor-powered machine designed for large-scale grass cutting. Its defining feature is its 72-inch (6-foot) cutting width, which allows it to cover a substantial amount of ground with each pass. This mower is built to be attached to a tractor’s three-point hitch and utilizes the tractor’s Power Take-Off (PTO; more on this later) to drive its cutting blades.

The Art of the Cut: 72 Inches of Efficiency
The 72-inch cutting width is crucial for efficient. With each pass, the mower covers a six-foot-wide swathe of grass.

Rear Discharge: More Than Just Convenience

The “Rear Discharge” in the RFM-72-YK’s name refers to how it handles grass clippings. Unlike side-discharge mowers, which eject clippings out the side, a rear-discharge mower distributes them evenly behind the machine. This seemingly small difference has significant advantages:

• Even Distribution: Rear discharge prevents the buildup of thick clumps of clippings, which can smother the grass underneath and create unsightly rows.
• Improved Mulching: The finer, more evenly distributed clippings decompose more quickly, returning nutrients to the soil and promoting a healthier lawn. This is a natural form of fertilization.
• Reduced Windrowing: Side-discharge mowers can create windrows (long, narrow piles of clippings), especially in thick grass. Rear discharge minimizes this issue.
• Safety: Side-discharge mowers can sometimes eject debris at high speeds.

Grass Types
There are many kinds of grasses, RFM-72-YK can handle them all. It is worth knowing about the different types, a few examples are:
Bermuda Grass:
Kentucky Bluegrass
Zoysia Grass
Tall Fescue

Following the Contour: The Magic of the Floating Hitch

One of the biggest challenges in mowing large areas is dealing with uneven terrain. A rigid mower can scalp high spots (cutting the grass too short) and leave low spots uncut. The RFM-72-YK solves this problem with its Category 1 free-floating flex hitch system.

Imagine a car’s suspension system, which allows the wheels to move independently of the chassis, absorbing bumps and keeping the car level. The RFM-72-YK’s floating hitch works on a similar principle. It allows the mower deck to move up and down independently of the tractor, following the contours of the ground. This ensures a consistent cutting height, even on rolling hills or undulating fields. The result is a smooth, even cut that enhances the appearance of your lawn.

Three Blades, Triple the Efficiency: The Cutting Powerhouse

Underneath the RFM-72-YK’s sturdy deck lie three heavy-duty cutting blades. This three-blade design is a key factor in its cutting efficiency. Here’s why:

• Overlapping Coverage: The blades are arranged to slightly overlap, ensuring that no grass is missed between them.
• Increased Cutting Speed: With three blades spinning at high speed, the mower can cut through thicker grass more easily than a single-blade mower.
• Finer Clippings: The multiple blades create a more thorough cutting action, resulting in finer clippings that decompose faster.
• Blades Material: The cast iron material is a great material for blades.

The blades themselves are mounted on cast iron spindles with ball bearings. Cast iron is an excellent choice for this application because it’s incredibly durable and resistant to wear. The ball bearings ensure smooth, efficient rotation of the blades, reducing friction and extending the lifespan of both the blades and the spindles. This robust construction is designed to withstand the stresses of heavy-duty mowing.

Driving the Cut: Understanding the Belt Drive System

The power to spin those three blades comes from the tractor’s PTO, but how is that power transferred? The RFM-72-YK uses a single-belt drive system. Think of it like the belt that drives the alternator in your car, but on a much larger scale.

The PTO shaft on the tractor connects to a pulley on the mower. A heavy-duty belt wraps around this pulley and another pulley connected to the blade spindles. As the PTO shaft rotates, it turns the belt, which in turn spins the blades. This system offers several advantages:

• Simplicity: A single-belt system is relatively simple, with fewer parts to wear out or break.
• Shock Absorption: The belt can absorb some of the shock from sudden impacts (like hitting a rock), protecting both the tractor and the mower.
• Easy Maintenance: Replacing a worn belt is a relatively straightforward task, compared to repairing more complex gear-driven systems.

Built to Last: The Strength of Steel

The RFM-72-YK’s durability isn’t just about the blades and spindles. The entire deck is constructed from heavy-duty steel. The top deck and side panels are both 3/16-inch thick. This robust construction provides the strength and rigidity needed to withstand the rigors of mowing over rough terrain and through thick vegetation. Alloy steel, in particular, is chosen for its high tensile strength and resistance to bending and cracking.

RFM-72-YK vs. The Competition: Choosing the Right Tool

While the RFM-72-YK is an excellent choice for many large-area mowing applications, it’s important to understand how it compares to other types of mowers:

• Rotary Mowers (like the RFM-72-YK): These are versatile mowers that can handle a variety of grass types and terrain. They are generally less expensive than reel mowers and easier to maintain.
• Reel Mowers: These mowers use a series of rotating blades that cut against a fixed bedknife, like scissors. They provide a very precise, clean cut, making them ideal for golf course greens and other high-profile turf areas. However, they are less effective on tall or uneven grass and require more frequent sharpening.
• Flail Mowers: These mowers use a series of free-swinging “flails” to cut vegetation. They are designed for heavy-duty cutting of thick brush, weeds, and even small saplings. They are not typically used for finish mowing, as they leave a rougher cut.

The RFM-72-YK’s niche is in providing a high-quality finish cut over large, potentially uneven areas. It’s a workhorse designed for efficiency and durability, making it a practical choice for farms, estates, and other properties with extensive lawns.

A User’s Perspective: Real-World Experience

Janet Ahrens, a verified purchaser of the RFM-72-YK, shared her initial impressions: “Took it out for a test drive. Mows very nicely… This will save my riding mower when cutting three+ acres of grass.” This feedback highlights the mower’s primary benefit: its ability to handle large areas efficiently. However, Janet also noted, “Lynch pins are a little iffy, I lost one and one of the bushings to adjust height. Would recommend change over to bolts once you decide how high you want to cut grass.” This is valuable constructive criticism, suggesting a potential area for improvement in the mower’s design. It also underscores the importance of reading the instruction manual (which Janet initially couldn’t locate) and performing pre-use checks.

Safety First: Operating the RFM-72-YK Responsibly

Operating any piece of heavy machinery, especially a tractor-powered mower, requires a strong commitment to safety. Here are some essential guidelines:

• Read the Manual: Before using the RFM-72-YK (or any equipment), thoroughly read and understand the operator’s manual. It contains crucial information about safe operation, maintenance, and troubleshooting.
• Pre-Use Inspection: Before each mowing session, inspect the mower for any loose bolts, damaged blades, or other potential hazards. Ensure all guards and shields are in place. Check the oil level.
• Clear the Area: Make sure the mowing area is clear of people, pets, and any objects that could be thrown by the mower.
• Engage the PTO Slowly: When engaging the tractor’s PTO, do so at low speed and gradually increase it to the recommended operating speed.
• Avoid Steep Slopes: Do not operate the mower on excessively steep slopes, as this can increase the risk of rollovers.
• Wear Appropriate Gear: Always wear appropriate personal protective equipment (PPE), including eye protection, hearing protection, sturdy work gloves, and steel-toe boots.
• Shut Down Safely: Before dismounting the tractor or performing any maintenance on the mower, disengage the PTO, lower the mower deck, set the parking brake, and turn off the engine.
• Regular Maintenance Check the oil, and grease regularly.

Keeping it Running Smoothly: Maintenance and Care

Regular maintenance is essential for keeping the RFM-72-YK in top working condition and extending its lifespan. Here’s a basic maintenance checklist:

• Cleaning: After each use, remove grass clippings and debris from the mower deck. A build-up of clippings can trap moisture, leading to rust and corrosion.
• Lubrication: Grease all fittings regularly, according to the recommendations in the operator’s manual. This keeps moving parts operating smoothly and reduces wear.
• Blade Sharpening/Replacement: Inspect the blades regularly for sharpness and damage. Dull blades tear the grass instead of cutting it cleanly, leading to an unhealthy lawn. Sharpen or replace blades as needed.
• Belt Inspection: Check the drive belt for wear and tension. A loose or worn belt can slip, reducing cutting efficiency. Replace the belt if necessary.
• Storage: When storing the mower for extended periods, clean it thoroughly, lubricate all fittings, and store it in a dry, protected location.

The Future of Mowing: Efficiency and Sustainability

The King Kutter RFM-72-YK represents a significant step forward in large-area mowing technology. However, the pursuit of even greater efficiency and sustainability continues. Future developments in mower technology may include:

• Electric Mowers: Battery-powered mowers are becoming increasingly popular for smaller lawns, and electric options for larger equipment are likely to emerge.
• Autonomous Mowers: Self-driving mowers, guided by GPS and sensors, could revolutionize large-scale lawn care.
• Alternative Fuels: Mowers powered by biofuels or other renewable energy sources could reduce the environmental impact of mowing.
• Smart Technology: Sensors and data analysis could be used to optimize mowing patterns, adjust cutting height automatically, and even detect potential problems before they occur.

The King Kutter RFM-72-YK is a powerful and efficient tool for maintaining large lawns and fields. By understanding its design, operation, and maintenance requirements, users can harness its capabilities to create and maintain healthy, beautiful landscapes for years to come.