The Bobcat 743 skid steer loader is a legend of compact equipment due to its durability, straightforward design, and reliable performance on farms and job sites. If you own one or are considering buying one, reading this guide is helpful. This guide will cover its core specifications, clarify the differences between its variants, diagnose common problems, and offer essential maintenance tips to keep it running strong.
Bobcat 743: Key Specifications & Dimensions
It was engineered with a perfect balance of power and size for its era, making it incredibly versatile. Its design became the foundation for its subsequent variations.
Operating Specs
| Horsepower | 36.0 HP |
|---|---|
| Lifting Capacity (35% Tipping) | 750 lbs |
| Lifting Capacity (50% Tipping) | 1300 lbs |
| Operating Weight | 4810 lbs |
| Tipping Load | 2600 lbs |
| Lift Breakout Force | 2749 lbs |
| Tilt Breakout Force | 2798 lbs |
| Max. Travel Speed | 6.0 mph |
Engine Specs
| Manufacturer | Kubota |
|---|---|
| Model | V1720 |
| Type | Diesel |
| Cylinders | 4 |
| Rated Speed | 2800 RPM |
| Torque Power | 1600 RPM |
| Combustion | Spherical (E-TVCS) |
| Compression Ratio | 21:1 |
| Firing Order | 1-3-4-2 |
| Gross Power | 36.0 HP |
| Displacement | 105.7 cu in. |
| Bore | 3.2 in. |
| Stroke | 3.2 in. |
| Peak Torque | 80 ft-lb |
| Coolant Capacity | 3.2 gal |
| Engine Oil Capacity | 2.2 gal |
| Fuel Tank Capacity | 23.0 gal |
Dimensions
| Height | 75.8 in. |
|---|---|
| Bucket Hinge Pin | 109.0 in. |
| Width | 55.1 in. |
| Length | 120.4 in. |
| Dump Height | 86.3 in. |
| Dump Reach | 21.8 in. |
| Ground Clearance | 7.5 in. |
| Dump Angle | 37° |
| Rollback Angle | 26° |
| Departure Angle | 28° |
Source: https://www.fabheavyparts.com/blogs/machinery-data/bobcat-743-data
Common Bobcat 743 Problems
As a piece of classic machinery, it has common wear-and-tear points that require attention. Identifying these early can save you from costly downtime.
Hydraulic System Issues
The hydraulic system powers the lift arms, bucket, and drive motors. Common issues include:
- Slow or Weak Hydraulics: This is often caused by low hydraulic fluid, a worn-out main hydraulic pump, clogged filters, or a faulty pressure relief valve.
- Hydraulic Leaks: Leaks are frequently found around cylinder seals (lift and tilt), worn hydraulic hoses, and the o-rings on the quick-disconnect couplers. Even small leaks can introduce air into the system and reduce performance.
- Lift Arms Droop: If the loader arms slowly lower on their own when the machine is off, it usually points to internal leaks in the lift cylinder seals or the main control valve.
Electrical System Malfunctions
Older skid steers like the 743 often face electrical problems, especially after decades of use. Common issues include:
- Safety Switch Failures: The Bobcat 743 relies on a seat bar safety system. A faulty switch in this system is a primary cause for the machine failing to start or the hydraulics refusing to operate.
- Starting Troubles: Beyond safety switches, starting problems are often traced to corroded battery terminals, a bad ground connection to the frame, a weak starter solenoid, or a worn-out ignition switch.
- Glow Plug Issues: The Kubota diesel engine uses glow plugs for cold starts. If one or more fail, the engine will be very difficult to start in cool weather.
Engine and Drivetrain Issues
The engine and drive system are the heart of the machine and require regular checks.
- Engine Overheating: Debris like dirt, grass, and dust can easily clog the radiator and hydraulic oil cooler fins, leading to overheating. Other causes include a failing water pump or a stuck thermostat.
- Drive Chain Problems: The drive chains can stretch over time, causing jerky movement or a “clunking” sound during operation. If not properly tensioned, they can damage the sprockets or even break.
- Fuel System Contamination: A clogged fuel filter is a common cause of power loss or engine stalling. A failing electric fuel shut-off solenoid can also prevent the machine from starting or cause it to shut down abruptly.
Bobcat 743 Maintenance Tips
Regular, proactive maintenance is the best way to keep your Bobcat 743 running strong and avoid major repairs. Here’s what to focus on:
Change Fluids and Filters on Schedule
- Engine Oil: Replace the oil and filter as recommended in the service manual to ensure engine longevity.
- Hydraulic Fluid: Clean fluid is critical for protecting the pump and drive motors. Change the fluid and filter regularly.
- Fuel Filter: A clean fuel filter prevents debris and water from damaging the sensitive injection pump.
- Air Filters: Regularly inspect and replace both the inner and outer air filters, especially when working in dusty conditions.
Inspect Hoses and Belts
At the start of each season, and before long jobs, visually check all hydraulic hoses and the main engine fan belt for cracks, leaks, or excessive wear. Replace any damaged components before they fail.
Keep Electrical Connections Clean
Periodically clean the battery terminals and the main frame grounding points to prevent corrosion. A wire brush and dielectric grease can prevent future electrical gremlins.
Fix Leaks Immediately
Even small leaks in the hydraulic or engine coolant systems can lead to major component failure if ignored. They also create a significant fire hazard when oily residue collects on hot engine parts.
Keep the Engine Bay Clean
Regularly use compressed air or a pressure washer (with care) to clean accumulated dirt and debris from the engine compartment, paying special attention to clearing the radiator and oil cooler fins.
Replacement Parts for Bobcat 743
Bobcat 743 vs. 743B vs. 743DS: What’s the Difference?
While the Bobcat 743, 743B, and 743DS models are nearly identical in size and power, their key difference in hydraulic flow is critical for matching the machine to the right attachments.
| Feature | Bobcat 743 | Bobcat 743B | Bobcat 743DS |
|---|---|---|---|
| Production Year | c. 1981 | c. 1991 | c. 1983 |
| Key Feature | Standard Model | Later Production Model | Dual-Speed Drive |
| Auxiliary Hydraulic Flow | 11 gal/min | 11 gal/min | 11 gal/min |
Conclusion
Now that you have a deeper understanding of its specs and variants. Knowing the subtle but important differences in its variants and taking proactive maintenance are the keys to its longevity.
Our guide and the lookup chart above are designed to help you quickly diagnose issues and find a solution. When it’s time to replace worn components, visit our website to explore the complete Bobcat 743 parts catalog, where you can enjoy easy ordering and a long-term warranty.
