Why Do Snowmobiles Overheat? With Causes And Corrections


On a cold day on the tundra, when your snowmobile gives off more heat than usual, you’re going to notice. At first, you write it off, thinking maybe your sled feels warm because of that large hill you descended or the cool trick you just pulled off. When the problem only worsens as your day goes on, you realize you need to do something. Why do snowmobiles overheat and how do you fix the problem?

Snowmobiles can overheat from overuse, lack of engine cooling, using the wrong fuel, and poor engine stator coil insulation. In some instances, bad electrical connections or a damaged voltage regulator-rectifier can also cause overheating. Besides refilling coolant and giving your sled a break, it’s not a bad idea to see a repairperson for an overheating snowmobile.

In this post, we’ll elaborate more on both the causes and corrections of snowmobile overheating. The next time such a thing happens to you when riding your sled, you’ll know just what to do. 

Let’s get started.

Why Do Snowmobiles Overheat?

First, let’s address the causes of snowmobile overheating. A bit of overheating, such as when you’re idling your engine, is normal. As you ride your sled, the heat exchangers will get coated in snow and the internal temperature of your snowmobile should then go down. 

However, in the following scenarios, overheating is usually indicative of a more serious problem, so make sure you proceed with caution. 

Overuse

How long have you ridden your snowmobile today? Has it been hours since you’ve taken a break? Maybe you’ve only gone for upwards of 60 minutes, but you were riding at exceptionally high speeds because you found a killer trial with lots of open space.

In both situations, you can expect your snowmobile’s engine tobegin overheating at some point. This issue will usually remedy itself upon you stopping the sled and hopping off for a while. Continuing to ride the snowmobile when it’s giving off a lot of heat could damage the engine and, in the most severe cases, lead to sled failure. 

Lack of Coolant or Oil

In our last article on how snowmobiles are cooled, we discussed that most sleds produced today use liquid cooling such as coolant. As the name tells you, coolant is designed to flow through the engine compartment and prevent the engine from getting too warm. 

You need to consistently monitor your coolant levels in your snowmobile. Without coolant, your engine is much more prone to overheating, so that could be one reason it’s happening.

Besides the coolant, another important fluid in sled care is the oil. When your snowmobile begins to run out of oil, the fuel mixture within can send heat to the engine, warming it up. If the engine gets hot enough, the rings and the piston heads can even melt, which will seize your engine and prevent you from riding any further. 

Broken Engine Fans

If a snowmobile isn’t liquid-cooled, then it has fan cooling. A series of fans near the engine blow cool air its way so the engine doesn’t overheat. One benefit of fan cooling is it’s usually more maintenance-free compared to using coolant…usually.

Any of those fans can stop working, and when they do, the cool air the engine receives may be insufficient to prevent overheating. 

Filling up with the Wrong Kind of Fuel 

Here’s a scenario that can afflict any sledder: you’re out on the snow when your snowmobile’s power begins to go, then there’s a death rattle, and finally, nothing. Your sled stops on the snow. Why? You had heard a strange sound before all this happened, but you didn’t think the situation was this serious. 

Using the wrong type of gas for your snowmobile can cause the sled to power down and stop working. For instance, oxygenated fuel, or that which is ethanol-blended, leads to a leaner fuel mixture that will affect your snowmobile performance compared to filling up with pure gas. 

If your gas has too much water in it, that’s also bad. Your gas may be waterier if it’s ethanol-based because ethanol promotes more water ingestion as it pulls in moisture from outdoors.

This combination of water and alcohol can outweigh the gas in your tank, separating and turning into gunk that can travel to your engine. Oh, and your gas, now separated from the ethanol and water, has a much lower octane rating than before. If you’re not familiar, the octane rating is a fuel source’s level of performance.

To avoid these fuel issues, never buy blended fuel. Also, go to a gas station with employees you trust who won’t steer you wrong. 

Bad Stator

Another part of your snowmobile that could contribute to overheating issues is the stator. What is the stator? Found in most electric engines, the stator is one component within a rotary system. Energy gets passed through the stator as the rotary system spins. 

The stator can go bad if you ride your sled for prolonged periods right after buying it, as the heat gets trapped within the engine. The stator’s insulation, which hides the stator wires, could begin to break down, increasing the risk of the wires short-circuiting. At this point, you’re at risk of engine failure. 

Degraded Electrical Connections

The wiring within the stator isn’t all that can fail. As snow gets into some parts of your snowmobile, the heat within causes the snow to melt. Instead of becoming a liquid, due to the high temperatures, the melting snow turns into steam. If you’ve had your sled for a while, the steam buildup could cause electrical connectors to break down, even if they’re weather-sealed. 

The metal terminals within the connectors will become corroded in a hurry. This increases your electrical system’s resistance, which can also affect your voltage regulator-rectifier. 

Worn-Down Voltage Regulator-Rectifier 

A voltage regulator-rectifier is a device that’s designed to control the voltage within the sled. However, due to the steam buildup that can destroy the integrity of the abovementioned electrical connection as well as raise the resistance of the electrical system, the wiring harness’ connectors can boost the output of the voltage regulator-rectifier.

What this means is that instead of managing voltage to a reasonable degree like the voltage regulator-rectifier usually does, it believes the electrical system can handle more voltage because its output has increased. As more voltage flows through the system, the stator gets overloaded and breaks down. 

How to Treat Snowmobile Overheating

Okay, so for one or more of the above reasons, your sled is overheating badly. You realize now that continuing to ride your snowmobile when it’s giving off so much heat is a very poor idea. Besides the engine, crucial interior components are also overheating, which could at any time cause the sled to stop working. 

Here’s what you should do when you feel your snowmobile get hotter than usual. 

Check Your Coolant Levels

First, you want to access your coolant tank to see how much coolant your sled has. We wrote about how to get to the coolant tank in our recent blog post about snowmobile cooling, so that’s worth reading if you haven’t already.

As we mentioned in that post, most snowmobile coolant is green or orange in color, so look for fluid in either of those hues. 

And Fuel Levels, Too

You should also check your fuel too while you’re at it. It’s best if you always fuel up fresh rather than use fuel you have sitting around at home (or elsewhere). Within about a month, blended gasoline is a gamble to use, and even pure gas might not be as pristine and clear as it once was. You can even speed along the gas’s lifespan by storing it in a vented container or the fuel tank, so don’t use either. 

Take a Break

If both your fuel and coolant levels are a-okay, then it’s time to move onto the other causes of your snowmobile overheating. For example, have you maybe ridden the sled too long or too quickly? If so, then the best thing you can do is take a break, aswe said before. This will give the internal components of the engine a much-needed chance to cool down so they can continue powering your ride for the second half of your day. 

Add a Radiator or Fan

What some sledders do to combat overheating is opt to add extra equipment to the rear of their snowmobiles. Either a radiator or an additional fan can keep air moving so the engine doesn’t get too hot, even if you ride for a while. 

This solution can work, but it does have several downsides. For one, you’re adding more bulk to the back of your sled, which can make maneuvering a little tough in some instances. Also, the outdoor temperature has to be especially cold. Otherwise, the fan is just blowing warm air into the engine, which will speed up its overheating. 

See a Mechanic 

If you’ve tried everything we’ve suggested to this point but your snowmobile still continues to overheat, then we’d recommend taking it to a sled mechanic. They can diagnose some of the more specific issues that can afflict snowmobile cooling, such as broken-down wiring or a failed voltage regulator-rectifier that you might not be able to detect yourself. 

Final Thoughts

Snowmobile overheating is a common issue, but it’s almost never one you should ignore. When your sled becomes hot, you’re at risk of your engine failing, as well as other parts of your snowmobile. 

Through this article, you now know just what to do when your snowmobile starts getting unusually warm. Good luck and stay safe out there!

Geoff Southworth

I am a California native and I enjoy all the outdoors has to offer. My latest adventures have been taking the family camping, hiking and surfing.

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