Compression Test: How To Perform On An ATV | Power Sports and More

When the weather warms up, it is time to pull out the ATV again. As you get ready to hit the trails, you need to think about the health of your engine. After all, you don’t want to climb into the mountains and have something go wrong while you’re up there. It’s always better to have a clear idea of how your ATV is performing before you take it out. This stops you from having any surprises when you are supposed to be having a good time.

One way that you can check up on how your ATV is performing is through a compression test. Now, if you are a first-time rider, you might not know the ins and outs of all of the maintenance and testing that your ATV needs to stay in good condition. The compression test might sound intimidating, but it is not. In fact, it is one of the easiest tests. Here, we have a quick walk-through of the steps that you need to take to make sure that your compression is accurate or at the very least, know when it’s not so that you can fix it.

The compression test simply tests your engine’s compression. It’s a quick process, where you take a device and hook it up to your engine. The device measures compression in pounds per square inch. What is great about it is that it usually will come with many adapters and gages that will fit your specific ATV. Without a compression gauge, you can’t expect to read your compression accurately. Do not use the finger test. Some people say that you can feel compression with your finger. While this is true, you are going to feel it no matter what, and this is an unreliable test.

Always use a compression tester to check compression. The point of the test is to see how the engine is performing. There is no other reliable way to check for compression, and any mechanic will tell you as much.

The Importance of the Compression Test

For all vehicles, regular maintenance is something that you have to do. It is true that usually, problems arise, even with proper maintenance. However, the issues that plague your ATV are going to be a lot worse if you ignore regular maintenance. A compression test is part of upkeep. Not only is it easy to perform, but it is one of the best tests to check on your ATV’s performance and the health of your engine.

You might be wondering what the point of testing your ATV is, but here are the main benefits and why you shouldn’t skip out on a compression test when you have the chance.

Performance Issues

If your compression is low, then your ATV is not going to run up to your standards. Likewise, if it’s too high, it’s not going to help your ATV perform. Sometimes, compression issues will cause misfires, or the engine might not start at all. In addition, your compression level warns you about other problems that might be developing. For instance, your first clue to a blown gasket might be your ATV’s compression level.

Compression tests tell you the current condition of your engine. Understanding the importance of your engine’s health makes it easy to tell why this would be such an important test to perform. If your engine’s health is low and you aren’t aware of it, this could cost you down the road. Maintenance on your engine, later on, can be more expensive than it would have been to deal with the problem as it was happening.

For everything that a compression test can tell you, it isn’t a difficult test to perform. If you have a compression tester, you won’t be spending a lot of time buried in testing or working on your ATV. It’s an easy test and barely takes ten minutes to perform on your own. You don’t generally have to have any special tools. Though, if your ATV requires specific tools to access the spark plug, seat and cylinder head, then those may be the only tools that you need.

Once you have the compression tester set up, it isn’t complicated to get your results. This isn’t one of those tests that require a lot of extensive knowledge, and by no means will you need the help of a mechanic.

How to Do a Compression Test

At first, a compression tester might look intimidating. Don’t be turned away by it, though, even with all the hoses or fittings, the test doesn’t take long, and it isn’t nearly as complicated as it looks. We have a simple step-by-step guide to help walk you through it. Remember, if you have any questions about your ATV or the compression tester, you can always consult a mechanic. Most of this, however, is relatively straightforward.

Check Battery Strength

Before you start, you don’t want to have a weak battery. Your reading is more likely to be inaccurate if your battery isn’t strong. This is because you can’t crank the ATV strongly and it will read weakly. So, if you do plan to test, make sure that your battery doesn’t have any issues that might affect the reading.

You don’t want the engine to be too cold when you start. The best tip that you can get when it comes to warming up your engine is to ride it for about ten minutes. Try not to heat it up too much, but once you have warmed it, you can begin the next process. Now, this is different for engines that you recently built. For instance, if your engine is new, then you want to ride for at least half an hour before you test it. Otherwise, the reading will be low.

For some ATVs, you will have to remove the seat to access the cylinder head. This isn’t true for all ATVs, however. If you know where the spark plugs are, your goal is to expose them so that you can remove it. You can use a magnet to remove the spark plugs, just make sure that you are careful.

For most ATVs, you will need to remove the seat to access the cylinder head. Then, with the adapter, you attach the tester to the cylinder head. Then, once attached, you can use the fittings to tighten it to the cylinder head with your finger.

The point is for you to have each cylinder within around 10 percent of each other.

Access the Throttle

Next, you need to open the throttle. Start your engine repeatedly, however your vehicle starts. For some, it may be a kick start, and others have a button to press to start up the engine. As you start the engine, you’ll see the pressure gauge move. This is how you can test your air compression.

The numbers are going to mean different things to your specific model. Once you have your numbers, you can check back with the manual to see if you are in the right range. The manual is going to tell you the right compression range and might also offer valuable information on what to do if you’re outside that range. If you do not have your manual, some vehicle manuals have postings online, and most mechanics can help you out to make sure that you are in the right range. One tip to keep in mind that anything less than 100 PSI means that there is engine wear.

Now, if it turns out that you had a low reading, you can put about two teaspoons of motor oil into the cylinder through the space for the spark. Once you do this, test your ATV again. This will tell you if the problem is with your valves. If the reading does not get better, then you probably have leaky valve seats, a bent valve or you may have to adjust your valves.

Conclusion: Compression Tests Are Necessary

You know what happens if you do not maintain your vehicles. Everyone knows that one person who always has their vehicle in and out of the shop and doesn’t bother with regular maintenance. Most of the time, people do pay for that. Not every issue is going to be loud at first. You can’t always tell that there is something seriously wrong with your off-roader until it’s too late. This is why there are solutions, such as compression tests that can tell you about the health of your engine before it’s too late. You don’t want to be out on the trails, kicking up mud, just to have your engine stammer or misfire.

Unlike some of the more involved maintenance, compression tests aren’t difficult. They have simple instructions, and anyone can perform them. It doesn’t have to cost you time or money with a mechanic. They are fast to do on your own and the devices themselves, if you choose to buy one, are not overpriced.