Top 11 John Deere X390 Problems (+ Troubleshooting Tips)

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Like every other John Deere mower, the John Deere x390 is a fantastic mower from the John Deere company that presents users with many excellent features. 

The John Deere company has been known over the years for its competence in the production and productivity of its mowers, even if it develops one or two faults that affect its functionality sometimes. 

Some common problems with John Deere x390 mowers include engine problems, electrical problems, machine problems like the mower lift latching, and several other minor problems like too much vibration and uneven cut. 

This article will address the major John Deere X390 problems alongside how to troubleshoot and fix them!

John Deere X390 Problems

Some of the common problems with the John Deere x390 mower models include the following; 

Engine Problems 

There are several engine problems that the John Deere x390 mowers develop while in use. 

Ranging from poor engine performance to an engine running unevenly. Some of the standard engine problems with the John Deere x390 mowers and their fixes are stated below:

See Also: John Deere X354 Problems

1. Poor Engine Performance 

This is usually the issue whenever you notice that you are running your John Deere mower, but the engine keeps going off midway through operation. Some common reasons this happens are dirt in your fuel system or making use of stale or wrong fuel. 

To Fix: The solution to this problem is straightforward, all you have to do is ensure that you obtain your fuel from a different supplier and replace old energy before you begin any operation. 

Most suppliers that blend fuel usually mixes it with alcohol, and getting an alcohol-free fuel will solve the issue. Ensure that you clean the fuel tank before replacing the new fuel; a clean fuel tank is always healthy for your engine. 

2. Engine Refusing to Start 

There are three significant reasons why this happens: the brake pedal not being depressed, engaging your mower or the PTO before the operation, and operating your mowers with a defective brake, key switch, or mower engagement. 

To fix: Ensure that your crucial switch, brake, and mower engagements are all in the right shape and that you should replace anyone defective immediately. 

Also, operate your mower only when the brake pedal is depressed, and the mower or PTO is disengaged. 

3. Difficulty In Starting the Engine 

In several cases, your mower would be tough to start, and you have to troubleshoot the mower to be sure what the problem is. 

Some common reasons why this happens include; the carburetor not being appropriately adjusted, using lowly viscous engine oil, operating your mower with a faulty spark plug, making use of stale or improper fuel during operation, and working your mower with a clogged fuel filter. 

To Fix: The first step you should take is checking on your fuel filter. Inspect it for dirt and debris because whenever this dirt goes into the fuel filter, it restricts it from letting fuel get to the engine; hence, the engine is difficult to start. 

Adjust your carburetor correctly before the operation, and also ensure that you use engine oil of excellent grade before operating your mower. 

When you never notice that your spark plug is faulty or has been used for too long, ensure that you change it. 

4. Engine Runs Unevenly 

in some cases, you would notice that your engine runs and operates unevenly but not to worry, the fix to this issue is straightforward. You must troubleshoot your mower for problems like a plugged cooling fin, plugged fuel and air filter, stale or dirty fuel, and improper fuel usage. 

Once you check for all this and you notice which is causing the problem, you can now fix it. 

To Fix: In the case of a plugged fuel or air filter, all you have to do is unclog these filters by cleaning them; you have to drain the energy out first and, in the case where they are broken, ensure that you replace these filters with new ones. 

Ensure you return your fuel tank with better fuel after cleaning it up. It would help to reduce the risk of developing another issue. 

Electrical Problems

These are problems that have to do with the electrical components of the John Deere mowers. 

Issues that involve the batteries and the light of your mowers. Below are some of the common problems you would encounter:

5. Battery Refusing to Charge 

Sometimes, you would notice that your John Deere mower would refuse to start up, and you wouldn’t even go to check the battery. 

Without the storm, the mower is as good as useless; therefore, it can also be a valid reason why your mower would refuse to start. 

Common reasons your battery would refuse to start include dead cells in your battery cables, dirty battery cables and terminals, and low engine speed. 

To Fix: You can fix this problem by cleaning up your battery terminals and cables and replacing your batteries if they have gone wrong. 

Please use the correct engine oil grade and ensure that it sometimes goes well before you return it. 

6. Lights Not Working 

You would need to use your mower in the evenings or even nights and you would definitely need your lights, so what happens when these light bulbs refuse to turn on? Don’t worry, the problem might be a burnt light bulb or a disconnected light plug. 

To Fix: You can replace the bulbs with new ones to see if it works and check on the wiring. If you cannot do this alone, you can get someone to do it for you. 

Also check if you turned on the light switch because even as crazy as it seems, the case might be you forgot to turn on your light switch. 

Machine Problems 

The machine problems are just general problems that you are most likely to experience with your john Deere mower, model x390. Some of these problems include; 

7. Excessive vibration from tractors

Sometimes your tractor vibrates even when in operation, which can be very uncomfortable for many users. Common causes of this problem include dirt on the tractor sheaves and worn-out or damaged engine belts and attachments. 

To Fix: Ensure that you clean your tractor sheaves regularly to prevent this problem, and also, replace every workout Engine belt and attachment. 

8. Tractors Refusing to Move Even When the Engine Is Running 

Just as much as the engine is essential, several parts of the mower must function well for the tractor to keep moving. When this happens, you should check your parking brake, hydraulic oil, and the freewheeling lever. 

To Fix: Ensure that your parking brake is set to unlock so the mower can move, and check on the hydraulic oil. If the oil level is too low, the machine refuses to move even when the engine is set. 

Your wheeling lever has to be disengaged for this mower to work, so ensure that it is kept from an engaged position. 

9. Mower Lift Refusing to Latch 

In this case, ensure your mower deck is a manageable height. Ensure that your deck is at a leveled position. 

10. Uneven Cut 

This is another problem that has to do with your mower deck. When your mower blades cut grasses unevenly, the mower will not even perform the excellent work you set on the field. 

Common reasons this happens include blunt blades, unevenly leveled mower deck, unequal tire pressure, and moving too fast. 

To Fix: You can fix this problem by yourself. All you have to do is sharpen your blades and ensure that the mower deck is equal and not uneven. Sometimes, when the air pressure in one tire is more than the other, it can result in a crooked movement. All you have to do in this case is reduce one to match the other. 

After fixing this issue, ensure that you operate your mower at a constant speed, do not go too fast or too slow, or else your mower might just be missing out on the proper operation 

11. Belt Slipping 

belt slipping occurs when your john Deere x390 mower belt slips during the process. This can result from excessive debris in sheaves, worn-out belts, or incorrect seat belt tension. 

To Fix: Ensure that you clean up the sheaves to get rid of the dirt and debris, and adjust your belt to the correct level. Also, when your belt is worn out, replace it. 


All these problems listed above are fixable, and you do not have to worry too much or doubt the future competence of your John Deere mowers. 

After you have fixed this issue and maintained your John Deere x390 mowers properly, you do not have to worry much in the future.

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