8 Common kubota Rtv 400 Problems and Solutions

Kubota RTV 400 is one of the most popular utility vehicle used for a variety of tasks, from work to recreation. Despite being quite famous, there are a few complaints from the users about some of the issues that they face during usage.

This article will discuss common issues with Kubota RTV 400 and provide solutions for resolving them. We will cover problems such as engine starting issues, power supply problem, clogs in the air filter, oile leakage and more. Also, you will get to know how to troubleshoot these issues.

Lets move forward into a much more detailed information regarding the problems of this RTV and the solutions to these problems as a DIY individual.

Kubota RTV 400 Problems and Fixes At A Glance.

Ignition problems Check and tighten connection; change ignition coil.
Engine StallAir filter replacement; change the fuel
Loss of powerAdjusting or replacing the clutch
Insufficient power in the batteryReplacement or maintenance of the battery
Engine BackfiresReplace fuel; Replace spark plugs
Clog forming in air filterRegular inspection; replacement of air filter
Oil leaksFixing oil cap; replacing oil
Engine not startingInadequate fuel; gapping the spark plug

As you have now gotten an idea about the issue that you might be facing, let’s get down to a broad discussion of why these problems are caused and how to fix them.

1. Ignition Problems 

RTVs get created to be used ideally on off-road applications, including hunting, recreational off-roading, and various types of industrial work. However, the vehicle might turn over and stop starting in certain cases. This issue is most likely related to the ignition system. Especially if the ignition connections are loose, starting the RTV might be a huge problem. Incorrect timing of the ignition might as well be a problem.

Resolving the Ignition Issue:

  • To deal with the ignition issue, looking at the spark plug for the right gapping and dirt is the first place to start.
  • Once you know it is not a problem with the spark plug, you can continue inspecting the ignition coil.
  • In case of a burned-out coil, replacement would be the main solution.
  • If the ignition connections are loose, checking and tightening them should easily fix the problems.

2. Engine Stall

In the case of engine stalls, it might be harder for individuals to inspect and find out the issues. Engine stall might occur due to the following:

  • Dirt residue forming in air filters.
  • Clog forming inside of the exhaust.
  • Excess fill of engine oil.
  • Blockage in the fuel system

How to Troubleshoot Engine Stall?

  • If the engine is stalling due to dirt residue in air filters and exhaust, cleaning it thoroughly will do the trick. However, if the air filter is very old, it should be replaced.
  • If the engine gets flooded with excess oil, it should get cleaned.
  • If the fuel system has formed a blockage, cleaning the fuel system and removing the blockage would work fine.

However, if these solution doesn’t work, it is recommended to take a visit to the service shop.

3. Lack of Power

While riding the RTV, users may face a sudden loss of power in the engine. This might damper the vibe of the whole riding session.

This problem is mainly caused due to the following reasons:

  • Engine oil has run out.
  • Water mixture in the fuel.
  • Worn or defective spark plugs.

How to Solve the Lack of Power Issue?

  • Refueling the engine oil to an optimal limit will bring the power back again. 
  • Fuel mixed with water should be cleaned and replaced.
  • If the spark plugs are worn out, you can replace them or take an expert’s help.
  • If the fuel is of an incorrect grade, switch to a recommended fuel grade by the dealership.

4. Insufficient Power In The Battery

Throughout the years, due to continuous usage of RTV 400, users seem to face a common problem is that the battery is not charging properly. They might also face problems such as extra long charging time and the battery going dry and not working at all.

Before giving out the solution, let’s discuss ways to avoid such problems. The easiest way would be through well-run maintenance. Maintaining and keeping your Kubota RTV 400 on a regular check might help you avoid most of these issues.


  • To check for battery issues, use a voltage meter to check if the output is put at 12v. If there is a fluctuation in the voltage, it means the battery has gone dry.
  • If the battery has gone dry, the only solution is to replace the battery.
  • If the battery is not dead but has a lower voltage, recharge it to 12.5V.
  • Do note that the battery should always be charged with a Trickle charger; otherwise, it might be damaged.

5. Engine Backfires

A scarifying problem that some users of RTV 400 face is that the engine tends to backfire, making a large explosive noise. While this problem is rare, it is not that much serious. The most common reasons behind the backfire include:

  • Weak or damaged spark plugs with little gapping.
  • Old as well as low-grade fuel being used.


  • Re-adjusting the spark plug gap would be the very first attempt. If the spark plugs are damaged excessively, then replacement is required.
  • Old fuel should be pumped out and replaced with new oil. Switching to a high-grade recommended fuel by dealers would be highly recommended.
  • However, there are as well some issues that might be too hard for the DIY. These problems include ignition timing failure, Mechanical failure, and incorrect installation of spark plug wirings. These problems require professional attention; thus, visiting the local mechanic would be a good idea.

6. Clog Forming In Air Filter

As you can use RTV for various purposes in different environments, so usage clogs might form in the air filter. This would lead to exhaust overheating and might lead to various dangerous outcomes.


  • If the air filter is fairly new and has formed a clog, cleaning it thoroughly might be a good start. Using an air blower to get rid of the dust is also a good idea.
  • If the air filter is in use for an extended period of time, it is a good idea to replace it with a new one.

7. Oil Leakage

Sometime, the rides on a Kubota RTV 400 can become quite bumpy. This might cause cracks and bolts to loosen up. Thus bringing forth the problem of possible oil leakage. There might be cases that the oil is not leaking from broken seals; however, the rough course track is contaminating the oil.


  • If the bolts of the engine are loosened, tightening and refueling the tank will get rid of the leakage.
  • In case of a crack, it has to be repaired or replaced to fix the problem.

8. Engine Not Starting

This is a fairly common issue even new users have faced. Even though the main reason might seem silly, it slips the mind of people. Inadequate fuel might be one of the main reasons. Other reasons include improper gapping in the spark plugs or the RTV cabling to deteriorate.

How to Start the Kubota RTV 400’s Engine?

  • Removing the spark plugs, cleaning them, and re-gapping should make the engine run smoothly again. In certain cases, the spark plugs might have been exposed to excessive grease and dirt, thus needing a replacement.
  • If the cabling has deteriorated, it is recommended to ask for help from a professional, as the cabling is hard to replace by regular users.

Final Words

After conducting thorough research, we have found out that the issues in Kubota RTV 400 are quite moderate and are mostly simple at the expense of a few hundred dollars. However, there are also some of complicated issues that might exist. Therefore in such instances, a quick visit to the service shop might be beneficial.

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