If you’re noticing smoke coming from your ATV, it can be a cause of concern and sometimes it’s nothing.
The color of the smoke will determine what problems, if any, that your ATV has and what you should do about it.
In this post, I want to go over what causes an ATV to smoke, what the different colors of smoke mean, and what to do to keep your ATV from starting to smoke or even overheat.
Why Is Your ATV Smoking?
Your ATV can start to smoke or emit burning smells for many reasons. The color of the smoke, the location, and how it started can tell you what problems you have and what to do about it.
Below, I go over the colors and all the reasons an ATV will smoke and what you can do about it.
1. White Smoke:
- Cold start – When starting an ATV, it’s not uncommon to see some smoke come out the tailpipe as the hot air meets the cool air. You may even see some moisture. If you see smoke for a brief time when you first start your ATV for the ride, then it’s not a concern.
- 2-stroke – If you have a 2-stroke ATV, then your ATV burns oil and seeing some smoke coming from the exhaust is normal. You may even have a huge plum of white smoke if the carbureted ATV has been sitting for a while. This is normal for a 2-stroke, especially when starting it, to see white or often blueish gray smoke come out the pipe.
- Water In Cylinders – If you got water in your cylinders of your ATV, then seeing white smoke would be expected.
- Coolant leak – If the ATV’s coolant is getting into the combustion chamber, it can result in white smoke from the exhaust. A blown head gasket or a cracked head or cylinder is often the culprit.
- Burning Oil – Just like with 2-stroke that burns oil, if your 4-stroke is burning oil then white smoke can be seen. This could be due to worn valve seals, piston rings, or other internal engine issues.
2. Blue / Gray Smoke:
- Too Much Oil – If too much oil has been added to the engine, it can result in blue smoke. Always ensure you’re filling to the correct level.
- Burning Oil: This usually indicates that oil is being burned in the combustion chamber. Potential causes include worn piston rings, valve seals, or a malfunctioning PCV valve.
- 2-stroke – Blue or gray smoke is more common on 2-stroke ATVs as they burn the oil. The color can be white, blue, or gray, but smoke at the start of turning the 2-stroke on is common, especially if it’s been sitting.
If you’re seeing blue or gray smoke, and you don’t have a 2-stroke ATV, then something seriously wrong with your ATV. The dealership or local repair shop is needed if you don’t know what you’re doing.
3. Black Smoke:
- Rich Air/Fuel Mixture: Black smoke usually indicates an overly rich air/fuel mixture. This means there’s too much fuel and not enough air entering the cylinder for combustion. It could be due to a faulty injector, a clogged air filter, bad sensors, clogged carburetor and more. I suggest replacing your spark plugs first if you’re getting black smoke.
- Dirty Air Filter: A clogged or dirty air filter can restrict the amount of air going into the combustion chamber, causing an imbalanced air/fuel mixture. I’ve even seen dirt daubers, mice, and mud make its way to the intake and restrict airflow. Take the air filter out and see what is blocking when you have black smoke.
4. Burning Smell
If it smells like your ATV is burning, has a rubber burning smell or similar, then check out my guide here on how to fix it.
5. Electrical Burning
Electrical fires have their own unique smell and color to them. Electrical smoke and fires often smell like burning rubber as the wires melt.
You can also see blue or white smoke coming from electrical fires, and it must be put out quickly or the whole ATV will burn.
Electrical fires are more likely to happen near parts of the ATV that consume a lot of power, like the starter, winch, relay and similar areas. Pay close attention to these areas if you smell or see smoke to see if it’s an electrical fire. It’s often a short somewhere, and it can be accompanied by a check engine light or the ATV not running right.
Sometimes it’s as simple as your ATV being dirty and that is why it’s starting to smoke.
I see guys with mud on their radiators and damaged radiator hoses complain their ATV smokes, but all they need to do is either clean the ATV from mud or fix the hoses.
Why Does An ATV Smoke?
The biggest reasons ATVs smoke is often from the lack of maintenance or not driving them enough.
Oil, spark plugs and other major parts of your ATV wear out and when they do, it causes all kinds of running issues. You need to do routine maintenance on your ATV to keep it in good running condition.
You also need to drive your ATV often or perform long-term storage on it if you’re not riding for a few months or more. It’s common for an ATV that’s been sitting for a long time to smoke due to the condensation that builds up in the pipe, gas going bad, and the oil and parts wearing out from inactivity.
Avoid Submerging Your ATV
With so many people mudding their ATVs and completely putting them in the mud, it’s more common to see smoke.
A hot engine touching cool water will create smoke and steam. This water can find its way into places and stay there until it’s broken free later, and then you see smoke as it hits the hot engine.
If you’re mudding your ATV a lot, you can expect to see more smoke, but you still need to keep an eye out. If you can, avoid completely putting your ATV in water or mud.
Understanding the reasons behind an ATV’s smoking is important in keeping it going for a long time.
As talked about, the color and nature of the smoke and where it’s coming from, can provide valuable diagnostic cues. Whether it’s the common white smoke of a cold start or the more concerning blue smoke indicating burning oil, being proactive in addressing these signals is key.
Remember, routine maintenance, staying on top of changes, and addressing issues head-on will not only reduce the chances of your ATV smoking but also prolong its life.