9 Most Common John Deere x304 Problems & Solutions

The x304 sits at the lowest end of the John Deere x3 range and is geared primarily towards the homeowner or for very small commercial applications. It’s well-priced, feature-rich, and has even been described as being genuinely fun to drive.

But does this cheap price tag and the fact it was not designed for demanding large-format mowing mean that it’s poorly made?

Absolutely not! This is a reliable and versatile mower that, when maintained, is going to serve you very well. However, there are some problems and maintenance upkeep you will need to be aware of should you decide to purchase this machine.

So in this article, we’ll cover all the main problems you will encounter with the machine and show you how to fix them too.

The most common problems with the John Deere x304

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Even with being one of the lower-end models within the x3 range, it still packs all the same features and excellent quality-of-life aspects that its bigger brother, the x324, has, just to a lesser extent.

For your money, you still get the same comfortable chassis, an 18.5 horsepower Kawasaki engine, and a 3.3-gallon fuel tank. That, combined with the cruise control function, provides a relaxing and stress-free mowing experience.

Despite the user-friendly features and John Deere’s efforts to make it as easy to operate as possible by non-professionals, the mower has some issues you will need to contend with. 

The primary problems the x304 faces are the engine, electronics system, and mower blades. Let’s take a deeper look into these issues and how you can go about fixing/maintaining them.

1. Engine not starting

One problem you are very likely to encounter is the engine not starting. While this can, at first glance, is quite alarming, don’t worry! The problem isn’t usually as serious as it might seem.

Several minor issues can contribute to the engine being unable to start, most of which are easily fixable with some good regular maintenance and upkeep.

  • The first thing to check is that the engine has enough fuel. If the fuel tank is not filled up enough, re-fill it with new, high-quality fuel.
  • If there’s already enough fuel in the tank, ensure that’s is using new fuel, as over time, fuel quality can degrade. So if the machine has been idle for some time (for example, over the winter), it’s not uncommon to find it’s not usable. Discard the old fuel and replace it with new fuel.
  • Check the fuel system isn’t dirty. Lumps or debris within the fuel system can interrupt fuel flow and prevent the engine from working correctly.
  • Likewise, you should also check the fuel filter is not clogged, as this may also prevent fuel flow into the engine.
  • Finally, you should check the spark plug. This is responsible for generating a tiny spark that ignites the atomized fuel. So if this breaks, the lawn mower will not be able to start. These are cheap and easy to replace, so throw out the old one and install a new one.

2. The engine runs rough

You may find that even if you’re able to get the engine started, it doesn’t appear to be running well, which can include odd noises, extra vibration, and uneven acceleration.

The first thing to check is the cooling fins which are there to help dissipate heat from the engine. When these are blocked, the heat cannot leave the engine, resulting in poor performance. Clean and wash these fins out.

Next, you should inspect the electrical system. If any contacts have become corroded, detached, or broken, these will need to be repaired or replaced accordingly.

Finally, you should check the air cleaner element,  designed to remove dust from the air before it gets into the engine. If this becomes clogged up, the engine cannot get a consistent air supply, resulting in a rough-running engine.

3. The mower suddenly turns off

If your mower is turning itself off seemingly randomly, you should check the spark plug wire to see if it has failed and replace it accordingly. Then you should check the ignition coil and replace it if it’s defective.

Finally, check the carburetor, responsible for supplying the engine with the correct air and fuel ratio to let the engine run. It may need adjusting to get the correct balance between the two.

4. Overheating problems

When the mower overheats, not only will it result in poor performance and uncomfortable operation of the mower, but it can also accelerate component wear resulting in expensive replacements much sooner than expected.

If your mower is overheating, you should first look at reducing the load put on the engine. This can come in the form of slowing the machine down, being aware of steep inclines that may cause the engine to struggle, and even lowering the mower blade speed to give the machine an easier time.

In addition, you should once again check that the cooling fins are clear. Then check the oil to ensure there’s enough in the tank. Also, if the oil is already quite old, it’s often a good idea to replace it with new oil.

Finally, you should check the mower’s idling speed to ensure it’s not too fast.

5. Engine floods with fuel

If the engine seems to be getting too much fuel, the first thing to adjust is the carburetor. But if the problem persists, you may need to adjust the choke cable to help restrict the amount of fuel making its way to the engine.

6. Black smoke emits from the exhaust

If you find black smoke appearing from the engine, it usually means an excess of oil being burnt off. The two primary contributors to this are the air filter element being plugged up and the throttle not being fully engaged, which may need adjusting.

7. Battery doesn’t charge

When the battery doesn’t charge, it indicates that the cells inside the battery are dying. Unfortunately, there is no easy way to repair this, and we recommend removing the old battery and replacing it with a new one.

8. The belt is slipping

The main drive belt slips can make for an uncomfortable and inconsistent mowing experience. 

You should inspect the belt to see if it’s worn, look for cracks or frayed edges, and if it looks old, you should replace it with a new one.

If the belt still seems in good condition, it may be a problem with low belt tension. Here you should adjust the tension so it won’t slip.

There may also be dirt in the pulley which needs to be cleaned out.

9. Poor cut quality

Over time it’s pretty standard for the cut quality of the mower to degrade a little. A number of factors that can contribute to this are easily solved with a bit of general maintenance.

  • Check the deck level isn’t too low, as there needs to be a good ground clearance for the blades to cut correctly.
  • There may be uneven tire pressure causing the deck to lean down in one corner, which is a surefire way not to get an even cut.
  • If you are operating the mower at a fast speed, try slowing it down a bit to give the blades time to cut the grass properly.
  • Finally, check the mower blades are not dull. They should be resharpened periodically to ensure they can cut the grass well.

John Deere x304 Problems: are they a deal-breaker?

When purchasing a mower intended for smaller operations, much like the x300, it’s essential that it’s not overly complicated and requires a lot of technical and mechanical knowledge to keep it operational.

We feel the x304’s problems are nice and easy to deal with by keeping up with a solid general maintenance routine. Anyone can do this, and it doesn’t require too much time.

Therefore, we highly recommend the x304 as a solid and reliable machine that will serve you well, even if you don’t have a high degree of mechanical skills.

5/5 - (6 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.