A decreasing oil level or blue exhaust smoke indicates that your ATV burns oil. However, these symptoms don’t always mean total disaster. But we care for our machines and assume the worst when things like this happen, so it’s better to have it checked out.
Knowing more about what’s causing your ATV to burn oil will help you sleep better at night and may help you determine whether you need to address the cause.
The most common cause of why an ATV burns oil is worn or damaged piston rings or worn engine due to dirt bypassing the air filter. But it can also be caused by simply using the wrong type of oil for the specific bike.
A leak-down test will, in most cases, tell you if there is an issue with the engine, causing it to burn oil.
Please continue reading to learn more about the possible reasons why your ATV burns oil and what to do about it.
What Does It Mean When an ATV “Burns Oil”?
The term of a vehicle “burning oil” refers to when oil, for some reason, enters the air/fuel mixture and gets set on fire in the combustion chamber by the spark plug.
This fuel contamination disrupts the combustion process and may cause the bike not to perform as it should. It is also what’s causing blueish smoke to come out of the ATVs exhaust system.
Sometimes, people think their ATV burns oil simply because they have noticed decreased engine oil levels. However, more often than not, other reasons cause the levels to drop.
Common Reasons Why an ATV Will Burn Oil
Let’s explore the most common and less common reasons why an ATV would be burning oil. You may be surprised that some of them are not as disastrous as you feared initially.
Using the Wrong Type of Oil
Sticking to the type of oil the manufacturer recommends is usually a good idea. Using a different kind, or sometimes even just using another brand, will void your warranty.
Using mineral oil instead of synthetic oil or a different viscosity grade (thickness) than recommended may cause your ATV to burn oil.
Strange as it might seem, even using a different brand than what’s recommended may sometimes cause your bike to burn oil. Switching back to the one recommended by the manufacturer may be just what it needs.
But whatever you do, do not mix synthetic and mineral oil. If you are unsure what oil is on the bike, you need to replace it not to cause any additional engine issues.
If you bought the bike used, changing the oil is the first thing to try if it burns oil. You never know what type the previous owner put into it.
Regardless, it is not wasted time or money, as one extra oil change will only do good for your ATV.
Seized, Worn, or Damaged Piston Rings
A big part of the piston ring’s job is to keep oil from the crankcase from entering the air/fuel mixture in the combustion chamber.
If something prevents them from functioning correctly, small amounts of oil may leak past the rings, and the ATV may start burning engine oil together with the gas.
Over time the rings can wear down, causing a bad seal against the cylinder walls. Sometimes, pieces of the rings may break loose to be blown out through the exhaust system.
A quick compression test should tell you if the rings are ok. If you notice a puddle of oil in the bottom of the air filter housing, this would also be a strong indicator of bad piston rings.
If the bike has been sitting for some time, or if you only use it for some minutes each time without letting it heat up correctly, the rings may seize up. This will also create a bad seal, with oil burning as a result.
In the latter case, going for a long ride to warm things up may be all it takes for the rings to come loose and consequently fix your oil-burning issue.
Worn Cylinder, Valve Stem Seals, and Valve Guides
Any engine will wear over time. Not breaking in the bike properly or letting dirt get past a damaged or poorly seated air filter may speed up this process significantly.
As the engine wears, seals that need to be tight may start leaking. This way, oil can get places it is not supposed to be, like inside the bike’s combustion chamber. Here the oil will burn together with the fuel/air mixture.
To ensure optimum longevity, always follow the manufacturer’s break-in procedure when the bike is new.
And make it a habit to ensure the air filter cover is fitted correctly at all times and that no fastening clips are missing on the air filter cover.
Low Oil Level
That is right; too little oil may cause your ATV to burn oil.
The engine depends on oil for lubrication and cooling. When there is insufficient oil, friction between the different engine components increases.
This will, in turn, create more heat, sometimes enough to burn the oil that’s already there. The hotter the engine gets, the more oil it will burn.
You can start by adding the correct amount of oil to stop this vicious cycle.
Sometimes It Turns Out the ATV Does Not Burn After All
The rookie mistake of not checking the oil levels correctly, resulting in an inaccurate reading, is way more common than you may think.
When you check the oil levels (with the dipstick), the ATVe must be as level as possible. If it leans to one side when you check one day, but to the other the next day, you will get a different reading.
Ensure you compare apples with apples by doing accurate readings over an extended period to verify that the oil levels are, in fact, decreasing.
How to Tell if the ATV Burns Oil
Blue Exhaust Smoke
Blue or bluish smoke from the bike’s exhaust is usually a clear indicator of your ATV burning oil.
In this article, I dive a bit deeper into why blue smoke appears, plus how to troubleshoot and repair what’s causing it.
It’s worth noticing that blue smoke from a two-stroke is, in most cases, perfectly normal. When starting a cold two-stroke engine, left-over fuel and oil from the last time the engine ran will make the bike run a bit rich in the beginning.
This will create blue smoke.
But if the bike keeps smoking a lot when it’s warm, you should consider digging deeper into what’s causing it. I would recommend you begin by having a look at the jetting.
On the other hand, blue smoke on four-stroke bikes is not a good sign.
On the other hand, if the exhaust smoke is white, here is what causing it.
By Exhaust Smell
Oil being burned will create a distinct smell. Some, myself included, love the smell of burning two-stroke oil. Probably because it usually means I’m having fun. Others can’t stand it.
But if your four-stroke starts smelling like your lawnmower or chainsaw, the alarm bells should start ringing.
Oil Levels Decrease Over Time
If your oil levels decrease slowly over time, it may be a sign of your bike burning oil, but it may also be caused by a small leak somewhere.
Find a dry surface, like a clean garage floor, to park your ATV after riding. If there is a leak, you should notice a spot of oil underneath it after some time.
The leak may not even drip down on the ground if it is tiny. Check the underside of the engine to see if you notice any oil sweating out. You may need to take off any skid plates for better access to the engine.
Often you may see a drop slightly hanging down, but just not enough of a leak for the drops to fall on the ground. Also, inspect the area around the oil filter.
Not replacing or not correctly fitting the seal between the engine and the oil filter is a common cause of oil leaks.
If you find any leaks, this needs to be addressed to see if this fixes your issue with decreasing oil levels.
Does Burning Oil Damage the ATV?
The answer to this question is two-sided.
The actual process of your ATV burning oil does typically not cause additional damage to the engine. However, if oil levels drop below the minimum mark, it may cause damage from running it dry.
When there is not enough oil, the engine parts will not get the lubrication and cooling they need, potentially ruining the engine.
Depending on what’s causing the oil burn, it may be a sign of severe engine damage. In other cases, the issue can be easily fixed without risk of further damage.