10 Most Common Scag Patriot Problems

The Patriot Zero Turn mower by Scag Power Equipment was designed to provide a low maintenance yet high performance and robust mower with the working professional in mind.

With longevity and robustness as the crux of their design philosophy, the Patriot should be a machine that will serve you well for a long time with a minimal amount of maintenance.

Sounds great, right? Well, it’s worth noting that users of the Patriot have reported running into several issues after using the machine for a while.

Are these problems a deal breaker? Or are these everyday issues you would expect to run into on any riding lawn mower regardless of price and quality? In this article, we’ll take an in-depth look at these issues to answer these questions.

The most common problems with the Scag Patriot

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Much thought has been put into the Patriot design to lower maintenance and reduce potential problems. Including a long-life clutch brake, a reliable air-cooled V-twin engine, and fewer grease points which Scag says will ease the maintenance on the user.

All that, combined with a plethora of comfort and usability features, make using the machine a pleasure.

Yet still, the machine will run into some common engine problems, blade issues, and other less common issues.

So let’s look at the main issues the Scag Patriot will encounter. We’ll offer suggestions on how to fix/maintain them and finally say whether we think it’s a worthy purchase despite these problems.

1. The mower doesn’t start

When you’re ready to start the day, there’s nothing more troublesome than running into issues where the engine won’t start. So understanding what might cause this issue and how to fix it is a must as a Patriot owner.

Here are the primary factors that will contribute to your engine not starting up:

  • The first thing to check is the battery. Mainly if it’s been in storage for a while (for example, through the winter), the battery might have drained by itself. You should also check all electrical connections and ensure nothing has come loose.
  • Next, you should check the starter, responsible for generating a small electrical spark that ignites the fuel and starts the combustion process. If the starter is not working, replace it, as it’s a cheap component.
  • You should also check the spark plugs, making sure nothing is loose, and the connections are not dirty. Clean or replace as needed.
  • Check for adequate fuel in the tank, and check for any leaks that may lower the fuel level even after it’s been refilled. Also, if the fuel is too old, it should be replaced with new fuel as it can degrade over time.
  • The final thing to check is the fuel filter, which can become clogged over time, thus reducing the fuel the engine can receive. Clean this out if possible, or replace it if it’s already too old.

2. The engine produces smoke

Seeing smoke emanating from the Scag Patriot mower can be very alarming. But generally, this is just caused by excess oil burning off; perhaps the oil tank has been overfilled, which has caused some oil to leak onto the muffler.

You should check the oil level to ensure it’s not overfilled, and eventually, the issue should resolve itself once the oil has been burned off.

However, suppose you continually notice this for a prolonged period. In that case, it may indicate a leak in the fuel system, in which case you should inspect it thoroughly for any signs of leaking and fix it accordingly.

Additionally, you should inspect the air filter for debris, as a restricted airflow may cause the engine to overheat, causing black smoke. Clean or replace as necessary.

3. The cut quality is poor or uneven

As this machine is designed for the working professional, it’s extra important that the cut quality is maintained to keep your customers happy. However, as with any mower, the blades will dull over time, and the cut quality will decrease. So the mower blades need maintenance to keep the cut quality up to par.

The first thing to check is if the blades are dull, it’s recommended to resharpen the blades roughly every 25 hours of use, but this may vary, and you may find yourself needing to resharpen them sooner than expected.

Likewise, you should check the tire pressure is even across all tires. The deck will sink lower on one side if one is slightly flat, making the cut uneven.

Also, check that the drive belt isn’t old, frayed, or cracked, as this will result in the uneven spinning of the scag patriot mower blades. You can adjust it by making it tighter or replace it if it looks visibly old and worn out.

Finally, the last thing you can do to improve your cut quality is to reduce your operating speed. If you are working with damp grass, sometimes just slowing the drive speed down gives your blades an extra pass or two on each cut, which significantly helps the final quality.

4. Excessive vibration

With any high-powered machine, a certain amount of vibration is expected. However, if the vibration becomes excessive or uncomfortable, it may indicate a faulty or loose component that will need addressing.

  • Check the drive belt and ensure they are tight or not too worn. Sometimes they may also become twisted, which can damage them, so straighten them out and replace them if the damage is already too excessive.
  • Check all the mounting bolts on the deck, these are explicitly designed to reduce vibration when the commercial mower is running, but sometimes they may work themselves loose and go missing. Retighten any that are loose and replace any that are missing.
  • Give the whole commercial mower a check for any debris, rocks, acorns, or loose grass which has worked its way into the cutter deck. This is a fairly common thing, and as they rattle around under operation, they will dramatically increase the amount of vibration the machine produces.
  • Check that the mower blades are balanced. If they are not balanced, they will swing as the blades rotate, causing not only excess vibration but also a lot of strain on the bearings leading to faster component wear – fix this as soon as possible.

5. Unadjusted steering level

Many users report feelings of discomfort when operating the Patriot for long periods. But this scag lawn mower offers all the adjustments you could need to customize the fit to your preference.

So if you’re experiencing discomfort while using the machine, it’s worth checking that you’ve made every adjustment to make the riding experience more comfortable.

One of the primary points you should look at adjusting is the steering lever. This should be set to a height that’s comfortable for you. Loosen the knob, adjust the steering lever to your ideal distance, and adjust the seat height to match it. Retighten, and you should find your driving experience improves dramatically.

6. The Patriot keeps blowing fuses

Fuses are common points of failure, and anyone who uses these mowers for commercial purposes should keep a few around, just in case they die mid-job.

However, if you find that they are constantly blowing, a malfunctioning ignition switch may repeatedly be causing them to fail. Endlessly replacing fuses is not the best solution, and you should address the root cause.

Switch off the ignition key and remove the old ignition switch, then replace it with the new one. Now you should find your fuses last a great deal longer.

7. The scag lawn mower keeps turning off

Even after you’ve addressed the engine not starting issue, you may find that it still keeps shutting down mid-use, which is even more frustrating.

This is usually a fuel-related issue; as such, you should check that you have new fuel in and that it’s filled up to the correct level, as both old fuel and a low fuel level will sometimes shut your engine down.

The next thing to check is that the air filter is not plugged up with debris, as the engine needs to receive adequate air to function correctly. Clean the filter if possible, or if that’s not possible, replace it.

Then check the cooling fins as these can become packed with dirt over time, reducing the engine’s ability to dissipate heat due to reduced airflow. Clean these out and replace broken cooling fins to keep your engine cool and happy.

Finally, check the fuel lines and filter for any clogs that may block the engine from receiving fuel. Use a carb cleaner and compressed air to clean the lines out, or if the fuel filter is completely bunged up, it’s easier to replace the whole thing.

Finally, check that the engine has enough oil. Too much oil will increase the pressure in the crankcase, causing the engine to turn off. Likewise, too little oil will cause the engine to overheat – so ensuring you have a nice even level is vital.

8. The hydrostatic transmission is weak

Hydrostatic transmission uses oil in place to gears to transfer energy, which is great for efficiency and reducing component wear. But if you find that your machine seems weak and is struggling with heavy workloads, it may indicate a problem with the hydrostatic transmission.

Check the drive belt is not frayed, cracked, or too loose. Retighten as needed or if it’s already too old, replace it.

You should also check that the machine has adequate hydraulic oil, as a low oil level will weaken the system’s performance.

9. The mower can’t drive straight

This is commonly caused by incorrect tire pressure causing the deck to lean down on one side and pull the machine in that direction. So if you are having trouble keeping the scag mower straight, check that there is equal pressure in all the tires as detailed by Patriots specification.

You should also check the zero-turn dampers. If these go bad, they will jerk the scag mower to one side when trying to move forward. Replace these as necessary.

The final thing to check is the tracking. When using a zero-turn system, each wheel needs to turn at the correct rate. Otherwise, you will have trouble keeping control of the machine. Adjust the speed adjustment bolt to change the rotation speed of each tire so they are equal, as detailed in the Patriot manual.

10. The mower is leaking gas

If you smell gas when entering the lawn mower or you see a pool on the ground as you pull off, it may indicate you have a fuel leak somewhere on the machine.

There are many places on the lawn mower where the fuel leak could occur, so a thorough check of the system is in order.

It may be due to a dirty or failing carburetor. It can collect a buildup of substances over time, causing a blockage that will make fuel back into the system and leak. So clean the carburetor if possible and replace any damaged parts.

The fuel filter may also degrade over time and need replacing, and it’s the same for the fuel pump.

You should also check the fuel shut-off valve and gas cap for any weak/compromised seals and replace them accordingly.

Try to introduce a fuel system check into your regular maintenance routine to prevent fuel leaks from getting too bad and causing a problem.

Scag Patriot problems: Are they a deal-breaker?

As you can see, there are quite a few issues you need to be mindful of as a Scag Patriot owner. But it’s important to remember these are all common issues you will need to contend with on many other zero-turn mowers regardless of brand.

Overall the Patriot is a very reliable model and provides a solid and robust maintenance routine. We are confident you will be pleased with this purchase.

That, combined with many available accessories and minimum maintenance, makes this an excellent long-term investment for your mowing business.

4.9/5 - (7 votes)
( Farming Equipment Expert )

Marvin is an expert in farming equipment with a strong background in agricultural engineering. He graduated from Kansas State College of Agriculture, where he received a degree in Agricultural Engineering and specialized in farm equipment design and maintenance.