Every seasoned rider knows that when it comes to motorcycle performance, your engine's health is everything. Whether you're cruising the open road on a street bike or navigating rugged trails on a dirt bike, one component that plays a silent but critical role in keeping your engine performing at its best is the motorcycle coolant.
Coolant might not get the same spotlight as oil or fuel, but it's just as important—if not more so—when it comes to keeping your engine from overheating, preventing corrosion, and ensuring your radiator runs smoothly in all types of riding conditions. Let's break down why coolant matters, the types available, and how to properly maintain it so your bike keeps pushing forward without a hitch.
Why Coolant is Essential for Your Motorcycle's Radiator
Your motorcycle's radiator is designed to dissipate heat. But without coolant flowing through it, the radiator can't do its job. Coolant is the lifeblood of the cooling system—it circulates through the engine and radiator, transferring heat away from the engine and maintaining an optimal operating temperature. Without it, your bike would overheat in a matter of minutes.
How Coolant Prevents Overheating and Corrosion
The two biggest threats to any motorcycle engine are overheating and internal corrosion. Motorcycle coolant tackles both.
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Overheating Prevention: During combustion, your engine produces extreme heat. While engine oil does help with lubrication and some cooling, it's the coolant that absorbs the bulk of the heat and carries it away to the radiator. Once in the radiator, that heat is dissipated into the air, and the coolant returns to repeat the cycle. This continuous loop keeps the engine temperature within a safe range—even on the hottest days or during aggressive rides.
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Corrosion Protection: Coolants aren't just water with coloring. They contain additives like corrosion inhibitors, anti-foaming agents, and stabilizers. These additives prevent the metal components in the engine and radiator from rusting or corroding, extending the life of the entire cooling system. Without these inhibitors, your radiator's core, water pump, and coolant passages could deteriorate over time, leading to expensive repairs.
To put it plainly, skipping proper coolant maintenance or using the wrong type can leave your bike vulnerable to a whole mess of avoidable problems.
Types of Motorcycle Coolant and How to Choose the Right One
Not all coolants are made the same. If you've ever stared at a shelf full of antifreeze bottles, you know there's more than one option—and not every coolant is right for every motorcycle.
Glycol-Based vs. Water-Based Coolants: What's the Difference?
There are two primary categories of coolant: glycol-based and water-based.
Glycol-Based Coolants
These are the most common and come in either ethylene glycol or propylene glycol formulas. Ethylene glycol is highly effective at lowering freezing points and raising boiling points, making it a solid all-season choice. Propylene glycol is less toxic and more environmentally friendly but generally more expensive.
Glycol-based coolants are pre-mixed or available as concentrates. To avoid mineral deposits in your radiator, you should always mix them with distilled water—never tap water.
Pros:
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Wide operating temperature range
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Includes anti-corrosion and anti-foaming additives
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Longer shelf life
Cons:
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Can be toxic (especially ethylene glycol)
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Needs proper disposal
Water-Based Coolants
These are often used in racing applications. Water-based coolants typically contain corrosion inhibitors but lack antifreeze properties. They provide better thermal transfer than glycol but aren't ideal for freezing conditions.
Pros:
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Superior heat transfer
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Ideal for track or high-performance use
Cons:
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No freeze protection
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Shorter lifespan
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Requires regular flushing
So, Which Coolant Should You Use?
For most riders—street bikes, dirt bikes, ATVs, UTVs—a high-quality ethylene glycol-based motorcycle coolant is the safest and most versatile option. It works in a variety of climates and conditions. If you're racing or doing high-performance riding in controlled conditions, water-based coolants might offer a performance edge—but you've got to stay on top of maintenance.
When shopping for coolant, always check your owner's manual for manufacturer recommendations. Using the wrong coolant can damage seals, cause chemical reactions with existing coolant, or even corrode parts of your cooling system.
Best Practices for Maintaining and Replacing Motorcycle Coolant
Knowing what to use is only half the battle. Just like oil, coolant needs to be checked and replaced regularly to ensure your motorcycle radiator performs at its peak.
How Often Should You Change Your Motorcycle Coolant?
Most manufacturers recommend replacing your motorcycle coolant every two years or 24,000 miles, whichever comes first. However, that can vary depending on how and where you ride.
If you're putting your machine through rough terrain, extended periods of high RPMs, or riding in extreme temperatures, it's smart to inspect and replace your coolant more frequently.
Here's a basic maintenance schedule and checklist for coolant care:
1. Inspect Regularly
Check your coolant level every few rides or at least once a month. Your overflow reservoir should show whether the level is between the minimum and maximum markers. If it's low, top it off with the correct pre-mixed coolant.
2. Look at the Color and Consistency
Fresh coolant is usually bright green, pink, or orange, depending on the brand. If it looks cloudy or brown or has particles floating in it, it's time for a flush and replacement.
3. Flush the System
Whenever you're changing coolant types or at your regular service interval, flush the system completely. That means draining the old coolant, running distilled water through the system, and ensuring everything is clean before refilling.
4. Use Distilled Water Only
If you're mixing coolant yourself, always use distilled water—never tap water. Tap water contains minerals and contaminants that can cause deposits, clogging, and corrosion.
5. Bleed the System
After refilling, it's crucial to bleed any air out of the system. Air pockets can lead to hotspots in your engine and cause the radiator to work less efficiently. Start the engine and let it idle with the cap off until it warms up and the thermostat opens, allowing coolant to circulate and push out trapped air.
6. Check for Leaks
Periodically inspect hoses, the radiator core, and clamps for leaks. Any sign of coolant seepage could point to a weak connection or worn-out hose—deal with it right away before it becomes a bigger issue.
Why It All Matters
Look, we're riders. We live for the throttle, the twisties, the climbs, and the endless dirt trails. But we're also mechanics at heart. We know that the thrill of the ride means nothing if your bike can't take the heat—literally.
Coolant might not seem like a big deal until your temp gauge spikes mid-ride or you notice steam billowing out from your fairing. Don't wait for that to happen.
Proper coolant selection and maintenance are simple steps that go a long way in protecting your engine and your investment. Whether you're riding hard on a motocross track or logging highway miles on your cruiser, keeping your cooling system in check ensures that your motorcycle is always ready to perform.
Keep Your Radiator and Coolant in Check with Myler's Inc.
At the end of the day, it doesn't matter how much horsepower you've got if your engine can't stay cool. Choosing the right motorcycle coolant, changing it regularly, and keeping your radiator in top shape are non-negotiables for any serious rider.
That's where Myler's Inc. comes in. We don't just sell radiators—we live and breathe them. Whether you're on a dirt bike, a street machine, an ATV, a UTV, or even a snowmobile, we've got the best radiators, parts, and accessories to keep your ride running strong.
If your radiator is showing signs of wear, leaking, or just not performing the way it should, don't guess—contact us. We'll get you back on the road (or trail) with gear that lasts and performs. Visit us today, and let's make sure your bike is ready to go the distance.