Harley Davidson previously used the Twin Cam engine in their bikes. But from early 2017 and 2018, Harley has replaced all their Softail and touring bike models with Milwaukee-eight engines.
Both engines operate at optimal temperatures. Thus, the engines mustn’t get overheated. Otherwise, their performance will drop significantly. Overheating can reduce the lifespan of the different components and the engine itself. Hence, you must know the best way to cool a Harley engine to improve its performance and longevity.
You may choose air cooling, liquid cooling, and proper lubrication. Also, consider removing the thigh protector from the left side. Removing umbrella baffles from the engine side will cool it down efficiently.
What Is The Ideal Temperature For Harley Motorcycles?
As we talk about the Harley engine overheating and ways to cool it down, it’s better to know its operational temperature. Harley riders and experts suggest that these motorcycles operate at 180F to 200F (82-93°C) temperature. In summer it may increase slightly.
So, whenever you sense that the Milwaukee engine has exceeded its temperature range, you should rest it to lower the heat. If you continue pushing the engine too hard, it will reduce its performance. Also, running Harley in extreme heat will cost a loss in fuel economy.
Why Cool Down Is A Must For Harley Engine?
Harley touring and Softail motorbikes are the premium choices of stylish people. We know you all love riding your Harley motorbike, particularly when the weather is hot. Nonetheless, during the summer days, the engine of the Harley can become hotter than you imagine.
Both Twin Cam and Milwaukee eight engines operate best in 160°F to 230°F temperatures. In the most extreme scenario, the engine temperature shouldn’t go beyond 250°F. Therefore, the engine must remain at optimal temperature.
However, when the engine gets too hot, you need to find a way to reduce its temperature. There’re multiple reasons why you must cool down the Harley engine.
- A cool engine will last longer than an overheated one. Thus, you must try to cool off the engine to enhance the lifespan of its components.
- As the engine cools down, you will feel less heat on the motorbike. So, it increases your riding comfort and fun.
- A cooler engine can run with its full potential. So, you will see improved mileage and fuel efficiency with the Harley motorbikes.
- When the engine operates at its recommended temperature, it will work with increased power. Thus, you will see the difference in performance and mileage almost immediately when riding the motorbike.
- Lastly, cooling down the Harley engine will help you avoid explosions. Although it is a rare incident, you mustn’t compromise with safety features.
Long story short, cooling off the Harley engine will help you enjoy better engine longevity, less maintenance work, improved performance, and riding comfort.
The Best Way To Cool A Harley Engine
When you ride your Harley, you should ensure that its engine runs at optimal temperature. Thankfully, there’re multiple ways to cool off the engine and keep it running at standard temperature as recommended by the manufacturer.
Liquid Cooling System
Most motorbikes will have a liquid cooling system, and Harley bikes are no exception. When you apply liquid coolants to the engine, it will help dissipate the heat faster and better. Thus, the engine will operate within its recommended temperature.
However, when you buy any liquid coolants for Harley engines, you need to consider a few facts. Best coolants for motorcycles will have a higher water ratio than chemical coolants inside them. You may even apply distilled water with the coolant to increase its cooling performance.
Furthermore, you need to look at the freezing and boiling point of the coolant too. Technically, the freezing and boiling point of the coolant should be around -20°F to 200°F. Also, a pre-mixed coolant is better than a pure one. Considering all these facts, we found the Engine Ice Tyds008 High-Performance Coolant best for your Harley engines.
If you have a twin-cooled Harley engine, you should choose H-D Genuine Extended Life Antifreeze and Coolant. Harley recommends it for different engines. You don’t need to mix water with it as it already contains deionized water for a better cooling effect. It is silicate and phosphate free. So, it saves the engine parts from corrosion too.
Apply Proper Lubrication
Applying proper lubrication to the engine is one of the most common ways to maintain it. Also, proper oiling and lubrication help the motorcycle engine work in the best conditions. When there’s a lack of lubrication on the engine’s components, the friction of these components will increase. Consequently, the friction boosts the engine temperature.
Therefore, you should lubricate the Harley engine timely. Ideally, you need to replace your Harley motorbike engine’s mineral oil or lubrication once in 2000 to 3000 miles. For synthetic oil, you need to replace it once every 10000 miles.
When applying the engine oil to your Harley motorcycle, you must keep it slightly warm. This will yield the best result. Also, ride the motorcycle a few miles once you have applied the engine oil. It helps the engine soak the lubrication better. The AMSOIL FULL SYNTHETIC Motorcycle Oil 20W-50 works great for Twin Cam and Milwaukee-eight engine Harley bikes. It has 20W-50 viscosity and can work fine in extreme heat too.
Maintaining The Engine
Often, an older and not properly maintained Harley engine will overheat. It happens due to clogs in the coolant tube and radiator. Hence, you must always maintain the Harley engine. Ensure that the carburetor, radiator, and coolant tubes are clean.
After long rides, you should clean these parts. Also, use WD-40 cleaner to remove the clogs and rust. It helps the engine cool off properly without overheating issues.
Activating EITMS In Harley
EITMS stands for Electronic Idle Temperature Management, and it is available for all Harley made after 2016. So, newer Harleys have it. The system will help you manage the engine temperature whenever it goes beyond 165°C. So, you will always enjoy better temperature management with it.
However, in Harley, the system may be disabled. So, you need to enable the EITMS in Harley to control engine heat. You need to move the throttle of the Harley forward. Then, hold it until you see the indicator of the cruise control flash.
For details, you may see the following video:
When you enable the system, it will activate in the following four conditions. So, the engine won’t overheat for an extended period.
- The engine runs under 1200RPM
- Your vehicle is running below 1MPH speed
- The engine temperature has gone above 165°C
- The twist grip is in idle mode
As the preconditions show, EITMS will need activation during traffic signals. When you run the motorcycle freely on highways, it receives enough air ventilation. So it won’t get overheated. But, in traffics, it receives less ventilation. It, hence, requires the EITMS to cool off properly.
A Few Tricks To Cool Down Harley Engines
Although you can cool off the Harley engine with engine oil and liquid coolants, there’re other methods to cool off the engine. You may follow the below-mentioned techniques to cool off Harley engines and get better performance.
- You might consider removing the thigh protector on the left side of the motorbike. It improves the air ventilation through the rear cylinder and left side of the engine. As the air can easily flow through the left side, cooler air from the exterior will pass the engine. So, it helps in cooling the engine.
- Umbrella baffles and fork wings might increase the heat of the motorcycle engine up from 20°F to 25°. Thus, it is not good for Harley engines when you ride them at full speed. We suggest removing the fork wings or umbrella baffles to boost its heat dissipation performance.
- You might even try removing the catalytic converter of the Harley Softail and touring bikes. It is removable from the stock headers of the motorcycle. Although it doesn’t decrease the engine’s heat, it will help you feel less heat while riding the motorbike. Thus, your riding comfort will increase.
- You can also install a tank lift. However, avoid the deluxe option while mounting the new tank lift system. It will drop the temperature of the engine by 10°F to 15°F. Thus, the engine will operate at the optimal temperature with ease.
- Finally, the Cooling Deflector Wings will also be useful to cool off Harley Davidson engines. You can use the deflector wings even without the tank lift. It will reduce the engine heat by around 10°F.
Final Words
When you get a Harley motorbike, you will love to generate the best performance. Thus, maintaining the engine is mandatory. One way to maintain the Harley Davidson engine is to keep it cool in the long run. This guideline on the best way to cool a Harley engine should be useful in this regard.
You may expect to see a 5-degree to 10-degree reduction in the engine temperature with our suggestions. If you still find the engine getting hotter than usual, consider using a cooling fan with the engine. Plus, run a full check of the engine components from a nearby Harley store and follow their suggestions.