RDS691GKA523A3
Overview:
Radius S-Series with 23 HP* Kawasaki FR691 Engine and 52” UltraCut Series 3 Deck (Available Spring 2026)
With a compelling blend of speed, power, cut quality and value, the new Radius S-Series is the ideal zero-turn mower for home and acreage owners that demand advanced performance. Choose from 48-, 52- or 60-inch UltraCut Series 3 side-discharge cutting decks equipped with Exmark’s exclusive flow-control baffles for superior cut quality. The deluxe high-back seat features adjustable spring suspension, with molded flip-up armrests to deliver superior all-day comfort for operators of virtually any stature.
Radius S-Series models are designed for maximum durability with reduced maintenance needs. With just two annual grease points, low-maintenance HydroGear transmissions, reliable Kawasaki engines, and long-lasting components, the Radius S-Series is designed to run stronger and longer with less maintenance.
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Features
Full-Suspension Operator Seat
The Radius S-Series upgrades to a deluxe full-suspension operator seat to minimize bumps and vibration that reach the operator. When combined with the large 23-inch drive tires, the Radius S-Series delivers a smoother ride for increased operator comfort and decreased fatigue.
UltraCut Series 3 Cutting Deck
Fabricated and fully welded of high-strength steel, the UltraCut Series 3 cutting deck features Exmark’s exclusive Flow-Control baffles for Exmark Signature cut quality. Maintenance-free sealed bearing spindle assemblies and double-capture anti-scalp rollers offer increased durability with reduced maintenance requirements.
Integrated Hydro Pumps and Motors
Dual Hydro-Gear ZT-3100 hydro transmissions feature an integrated pump and motor design for maximum efficiency, long-term reliability and ground speeds of up to 9 mph.
High-Strength Fabricated Steel Frame
Fabricated and fully welded of high-strength rectangular steel tubing, the Radius frame places the heaviest components –– engine, transmission and fuel tank –– low and centralized in the frame. This lowers the machine’s center of gravity for increased traction and stability. New steel engine guards increase engine protection at the sides and rear of the machine, while also being easily removable for service access.
Easy Serviceability
With a floor pan and belt shields that remove easily, without tools, and an integrated jack receiver at the front of the frame, Radius models offer unparalleled maintenance access to the top and bottom of the cutting deck.
Upgraded Commercial Warranty
Radius S-Series models are covered by an extended 4-year/500-hour commercial warranty.
Specifications
| MODEL | RDS691GKA523A3 |
| UPC | 193308242460 |
| EQUIPMENT | |
| Width / Cutting Deck | 52" |
| Drive | Hydro-Drive |
| Starter | Electric |
| Steering Control | Hydraulically dampened twin levers adjustable both fore and aft. Also has 2-position height adjustment. |
| Caster Forks | .375" thick caster yoke arms. |
| Front Caster Tires | 13 x 6.5-5 smooth-tread, pneumatic. |
| Drive Tires | 23 x 9.5-12 K3012 |
| Safety Package | Operator Presence Controls (OPC) and drive system interlock. |
| Parking Brake | Automatic-actuated pawl brake. |
| Tractor Frame | Unibody, welded, heavy-duty 1.5" x 3" tubular steel. |
| Blade Spindles | No maintenance, sealed and non-greasable spindles; 7.75"-diameter cutter housing with 25mm (.98") diameter spindle shaft. |
| Cup Holder | Yes |
| Electrical | 12 volt battery with 15-amp alternator |
| Standard Features | Hour meter, cup holder, hitch, suspension seat |
| Seat | Deluxe, two-tone, bolstered suspension seat with flip up armrests and 3" travel |
| Optional Features | Hour meter, suspension seat and armrests |
| POWER COMPONENTS | |
| Engine Brand | Kawasaki |
| Transmission Brand | Hydro-Gear |
| Transmission Speeds | Infinitely Variable |
| Engine Model | FR691 |
| Engine Displacement | 691 |
| Engine Series | V-Twin |
| Fuel System | Carbureted |
| Speed | Infinitely variable speed selection from 0-9.0 mph forward, 0-4.5 mph reverse |
| Transmission | Hydrostatic |
| Engine Spec | AS43-R |
| Engine Speed | 3,600 rpm |
| Air Filter | Standard Engine Manufacturer's air filter |
| Fuel Capacity | 7-gallon single fuel tank with single fill location |
| Drive Description | Two Hydro-Gear ZT-3100 hydro static transmissions with no hoses and integrated cooling fans and integrated reservoir |
| Fuel Type | Gas Carbureted |
| PTO Engagement | Electromagnetic 105-ft-lb clutch |
| Drive Wheel Release | Allows unit movement without engine running. |
| Fuel Indicator | Float gauge |
| Deck Lift | Foot pedal, single point drop pin HOC lift assist springs |
| Carb Compliant | No |
| ROPS | 2-post foldable ROPS standard with seat belt. |
| DECKS | |
| Deck Style | Floating Deck |
| Deck Style Description | Full-floating UltraCut Series 3, side discharge standard, with molded discharge chute and option to bag or mulch. |
| Deck Construction | 10-gauge top that is formed and welded, 7-gauge side skirt and .375" welded bumper. 4 point suspension. |
| Cutting Heights | 1.5" to 5.0" in 0.25 increments |
| Blade Tip Speed | Approximately 18,500 fpm |
| Blades | 3 Blades at 18.0" Length |
| DIMENSIONS | |
| Width | 64.3" |
| Height | 73.7" |
| Curb Weight | 881 |
| Length | 83.9" |