Harley Milwaukee 8 Problems: Its Signs, Consequences and Fixing Tips

With its iconic motorcycles and roaring engines, Harley-Davidson has long been popular as a symbol of American freedom and rebellion. However, in recent years, the company has faced a new challenge with introducing its Milwaukee 8 engine.

This new engine was meant to be a revolutionary step forward for the brand, promising improved performance and reliability. However, as with any newly introduced technology, some issues have caused concern among Harley enthusiasts and owners.

Here, we will delve into Harley Milwaukee 8 problems and explore the potential causes and solutions. As we strive to provide a comprehensive understanding of these problems, we will also discuss the steps that Harley-Davidson has taken to address these issues and ensure the satisfaction of its loyal customers.

Harley Milwaukee 8 Problems

A Brief Background Of Milwaukee Engine:

The Milwaukee engine, also known as the Milwaukee-Eight, is a line of V-twin engines produced by Harley-Davidson. They introduced it in 2016 as the successor to the Twin Cam engine. The Milwaukee-Eight engine comes in two displacements: 107 cubic inches (1,753 cc) and 114 cubic inches (1,868 cc).

This new engine design flaw brought significant power, performance, and smoothness improvements compared to its predecessor. It features four valves per cylinder head, hence the “Eight” in its name, and a single camshaft that operates all eight valves. The Milwaukee-Eight engines are popular for their increased torque, better fuel efficiency, and reduced heat production.

Symptoms Of Milwaukee 8 Problems:

Harley-Davidson, a legendary American motorcycle manufacturer, has long been cherished by enthusiasts for its iconic designs and powerful engines. Harley-Davidson introduced the Milwaukee 8 engine in 2017, one of its notable creations.

However, like any complex machinery, the Milwaukee 8 engine has encountered a few issues that have raised concerns among riders. Many signs will warn you about Harley Milwaukee 8 engine problems. When you know these problems, you can take preventive measures to fix them. Here are Symptoms Of Milwaukee’s 8 Problems:

  • Engine misfires
  • Loss of power
  • Engine overheating
  • Excessive oil consumption
  • Loud knocking noises
  • Difficulty starting the engine

Here Are The Details Of Harley Milwaukee 8 Problems And solutions:

Here Are The Details Of Harley Milwaukee 8 Problems And solutions

Harley-Eight is an engineering wonder for its most powerful motorcycles. The engine has enabled Harley to make their motorcycles bigger and ideal for longer rides with no performance drop. So, We expect the engine to deliver superior performance.

Of course it does! Nonetheless, in the past 4 years, we have seen motorcycle riders complain differently about the engine. It is seen in all three versions. For instance, Milwaukee’s eight 107 problems include oil wet sumping and power loss. So, we will show you its common problems and solutions to enjoy better performance. Here are Harley Milwaukee 8 problems And solutions:

Problem1: Overheating And Cooling System Problems

Overheating And Cooling System Problems

The Harley Milwaukee 8 engine has been popular to experience overheating and cooling system problems. These issues can arise for various reasons, such as improper coolant levels, malfunctioning thermostats, or a faulty oil pump radiator.

When the engine oil aeration overheats, it can reduce performance, damage, and even complete breakdown if not addressed promptly. To prevent overheating and cooling system problems with your Harley Milwaukee 8, it is essential to regularly check the coolant levels and ensure they are at the recommended level.


To address overheating issues, some potential solutions include:

  • Check the coolant levels regularly and top them up if necessary.
  • Inspect the cooling fans to ensure they are functioning properly.
  •  Cleaning the radiator and removing any debris or dirt that may obstruct airflow.
  • Verify that the thermostat is functioning correctly and replace it if needed.
  • Ensuring that the water oil pump issue is in good condition and replacing it if it is faulty.
  • Check for any leaks in the cooling system and repair them promptly.

Problem2: Oil Leaks And Oil Consumption Issues

Oil Leaks And Oil Consumption Issues

Oil leaks and oil consumption issues are common problems that Harley Milwaukee 8 engines may experience. These engines are famous for having issues with oil leaks, which faulty gaskets, seals, or other components can cause.

It is important to regularly check for any signs of oil leaks, such as oil spots on the ground or visible oil residue around the engine. Some Harley Milwaukee 8 engines may also suffer from excessive oil consumption. This means that the engine may burn or lose oil faster than normal.


Oil leaks and oil consumption starter issues can be common problems with Harley Milwaukee 8 engines. These issues can arise for several reasons, such as worn gaskets, seals, or O-rings, improper installation of components, or excessive vibration engine wear. To address oil leaks, it is important to identify the source of the leak first.

This can be done by inspecting the engine and related components for any signs of oil leakage. Once the source is identified, the affected gasket, seal, or O-ring should be replaced with a new one to prevent further leakage. It is recommended to check the oil levels regularly and monitor for any significant decrease to address oil transfer and consumption issues.

Problem3: Transmission And clutch Problems

Harley-Davidson produces the motorcycle engine model called the Milwaukee 8. While it has been well-received, like any other engine, it may also experience certain issues. One common problem reported with the transmission and clutch of the Harley Milwaukee 8 is difficulty shifting gears or slipping clutch.

Various factors, such as worn-out clutch plates, improper clutch adjustment, or a malfunctioning transmission, can cause these issues. If you are experiencing any transmission or clutch problems with your Harley Milwaukee 8, it is advisable to consult a certified Harley-Davidson mechanic or dealership for proper diagnosis and repair.


It is essential to regularly check the compression and condition of the cylinders in the Milwaukee 8 engine. One of the most common issues reported by Harley owners is the excessive heat generated by the Milwaukee 8 engine. Here is some information on transmission and clutch problem solutions for Harley Milwaukee 8:

  • If you are experiencing difficulty shifting gears or the transmission slips, it could indicate a problem with the clutch or transmission.
  • You should regularly check the transmission fluid levels and make sure they are appropriate.
  • If you notice any abnormal rattling noise or vibrations while shifting gears, it is advisable to have your bike inspected by a professional mechanic.
  • In some cases, transmission problems may require repairs or replacements, so it’s essential to address them promptly.

Problem4: Electrical System Problems

Electrical System Problems

The Electrical system problems with Harley Milwaukee 8 motorcycles can vary. Some common issues riders report include intermittent electrical failures, faulty wiring, and problems with the charging system.

These problems can result in issues such as the bike not starting, lights or indicators not working properly, or the battery not charging correctly. It is important to have these issues diagnosed and repaired by a qualified technician to ensure the proper functioning of the electrical system in your Harley Milwaukee 8.


If you are experiencing battery problems, such as a dead battery or difficulty starting the motorcycle, check the battery connections for any Loose piston or corroded terminals. Also, ensure the battery is properly charged and consider getting it tested or replaced if necessary. Remember, addressing electrical system problems promptly is crucial to avoid further complications and ensure a safe and enjoyable riding experience.

Problem5: Fuel System Issues And Fuel Economy Concerns

Fuel System Issues And Fuel Economy Concerns

The Harley Milwaukee 8 engine is known for its power and performance, but like any engine, it can experience fuel system issues and fuel economy concerns. Some common fuel system issues include clogged fuel injectors, fuel pump problems, and fuel leaks. These issues can lead to poor fuel delivery, decreased engine performance, and reduced fuel efficiency.

To address fuel system issues, it is important to maintain and clean the fuel injectors regularly, replace the fuel-air cleaner filter as the manufacturer recommends, and inspect for any signs of fuel leaks. Additionally, using high-quality fuel and following the recommended maintenance schedule can help prevent fuel system problems.


The Harley Milwaukee 8 engine has been known to have some fuel system issues and fuel economy concerns. Common fuel system problems include leaks, clogged fuel injectors, and faulty fuel pumps. These issues can lead to poor fuel efficiency and reduced performance. To address fuel system issues and improve fuel economy, it is recommended to:

  1. Regularly inspect and maintain the fuel system components, including fuel lines, filters, and injectors. Clean or replace any clogged or malfunctioning parts.
  2. Use high-quality fuel from reputable sources to avoid contaminants damaging the fuel system.
  3. Consider installing a fuel management system or tuner to optimize fuel delivery and improve efficiency.
  4. Practice proper riding techniques, such as avoiding excessive idling or aggressive acceleration, as these can negatively impact fuel economy.
  5. Ensure the motorcycle is properly tuned and serviced by a qualified mechanic familiar with Harley Milwaukee 8 engines.

Problem6: Exhaust System Problems And Performance Issues

Exhaust system problems and performance issues are common concerns in Harley-Davidson Milwaukee 8 motorcycles. Some potential exhaust system problems include leaks, rust, or damage to the pipes, mufflers, or headers. These issues can lead to decreased performance, reduced fuel efficiency, and increased exhaust noise.

Performance issues in Harley Milwaukee 8 motorcycles can manifest in various ways. Some riders may experience a lack of power, decreased acceleration, or difficulty reaching higher speeds. Other performance problems may include engine misfires, rough idling, or stalling.


Exhaust system problems can occur in Harley Milwaukee 8 motorcycles, leading to performance issues. Some common issues include leaks, clogs, or damage to the exhaust pipes, headers, or mufflers. These problems can result in reduced power, decreased fuel efficiency, and even engine overheating. To resolve exhaust system problems and improve performance, several solutions can be considered:

  1. Inspection and repair
  2. Upgrading the exhaust system
  3. Tuning and remapping
  4. Regular maintenance

Problem7: Suspension And Handling Problems

Suspension And Handling Problems

Suspension and handling problems can occur in motorcycles, including Harley-Davidson’s Milwaukee 8 models. Some common issues riders report include poor suspension performance, excessive front-end dive during braking, unstable handling at high speeds, and difficulty maintaining control on uneven or bumpy roads.

These problems can negatively impact the overall riding experience and safety. To address suspension and handling problems, it is recommended to consult with a reputable motorcycle mechanic or Harley-Davidson dealership. They can assess the specific issues with your Milwaukee 8 model and provide appropriate solutions.


To address these problems, there are several solutions you can consider:

  •  Upgrading the suspension components
  • Adjusting suspension settings
  •  Checking tire pressure and condition
  •  Wheel alignment
  •  Upgrading the steering damper
  • Riding technique and body positioning

Problem8: Oil Sumping And Power Loss Problem:

Oil Sumping And Power Loss Problem

One of the 2019 Milwaukee 8 problems that have hit the motorcycle hard is their oil sumping and leaking problem. The problem was first seen in 2019 touring models. It continued till 2019. Oil sumping happens when the oil builds up around the Cam’s gear case and crankcase. Usually, the oil should return to the oil tank when not in use.

However, when the oil sumping starts, the oil develops mostly around the crankcase. As it doesn’t return to the tank, it gradually starts leaking. It causes power loss. Also, riders will experience excessive friction when they drive the motorcycle. The problem gets bigger when you go on a long ride with the Harley touring models.


The oil sumping and power loss problem in Harley Milwaukee 8 engines refers to the issue where excessive oil accumulates in the bottom end of the capacity engine, leading to a loss of power and potential engine damage. This problem has been reported by some Harley Davidson owners, particularly those with Milwaukee 8 engines. The solution to the Oil Sumping And Power Loss Problem:

  1. Upgrading The Breather System: One solution is to upgrade the breather system to improve the oil scavenging process. This can help prevent oil from pooling in the engine’s lower end.
  2. Engine Tuning: Proper engine tuning can also help mitigate the oil sumping issue. Ensuring the optimized air-fuel mixture and ignition timing can improve overall engine performance and reduce the likelihood of oil sumping.
  3. Regular Oil Changes: Regularly changing the oil and using the recommended viscosity and type of oil can help prevent oil sumping. Clean oil reduces the chances of oil buildup and subsequent power loss.
  4. Consult With A Professional: If you are experiencing persistent oil sumping and power loss issues with your Harley Milwaukee 8, it is advisable to consult with a professional Harley Davidson mechanic or dealer.

Why Does It Happen?

As the oil builds on the crankcase, the suction side will fail to remove enough oil. The suction side is right, along with the oil pump. When the suction side fails, the flywheel will rotate when you start the motorcycle. Thus, the rotatory power will start moving the flywheel inside the oil. It makes the soil aerated.

As a result, the oil around the crankcase traps there instead of returning to the tank. Many say the Milwaukee Eight 107 problems regarding oil sumping and leakage are due to the inadequate stock oil pump. Harley has made the stock oil pump smaller than the motorcycle needs.

The Consequence Of The Milwaukee Engine Problems:

The Consequence Of The Milwaukee Engine Problems

When the rider faces 2019 Milwaukee 8 problems, it brings several consequences. The chain on my Harley Milwaukee 8 started to make strange noises after a few months of riding. You need to know these consequences to maintain the engine and motorcycle better. Here are the Consequence Of The Milwaukee Engine Problems:

  • You will experience frequent power loss and engine failure problems. It reduces the riding performance and smoothness of the engine. You will feel disgusted while riding the bike as it stops in the middle of the road.
  • In many cases, the engine will overheat. When the engine overheats, it not only results in improper riding, but the engine may burst out, too. Henceforth, your ride with the Harley touring bike will become risky.
  • Last but not least, you will lose a lot of fuel. It makes your rides costlier with less fuel efficiency. It is the last thing you would want.


Harley Milwaukee 8 problems include oil sumping, leakage, power loss, engine failure, and inability to accelerate the motorcycle. The problems become visible mostly during long rings due to oil development around the crankcase. All these aftereffects will result in an inappropriate and dissatisfactory riding experience. It all happens due to an inadequate oil pump of the engine.

Henceforth, the only solution to the Milwaukee 8 engine problem is replacing the existing oil pump with a stock 2020. You may, alternatively, use an aftermarket oil pump too. It will be truly pocket-friendly. You will also occasionally experience failure to accelerate your motorcycle. The problem becomes even more acute in long-distance rides.


Is The M8 Engine Reliable?

Yes, the M8 engine is generally considered to be reliable. Developed by BMW, the M8 internal engine imbalance is popular for its performance capabilities and durability. It is designed to withstand high stress levels and has been extensively tested to ensure reliability.

Is The Milwaukee 8 Better Than The Twin Cam?

The answer to whether the Milwaukee 8 is better than the twin Cam is subjective and depends on individual preferences. The Milwaukee 8 engine performance offers more power, improved cooling, and reduced vibration compared to the twin cam.

What Is Different About The Milwaukee 8 Engine?

The Milwaukee-Eight engine differs from its predecessor, the Twin Cam, in several ways. First, the Milwaukee-Eight has a larger displacement, with options of 107 or 114 cubic inches, compared to the Twin Cam’s 103 or 110 cubic inches.

What Is The Biggest Milwaukee 8 Engine?

The biggest Milwaukee 8 engine damage is the 117 cubic inch (1,923 cc) excessive engine vibration, available in certain Harley-Davidson models.

What Is The Strongest Milwaukee?

The strongest Milwaukee is subjective and dependent on the specific tool or equipment being referred to. Milwaukee Tools is a brand popular for its high-quality and durable products, so determining the strongest Milwaukee would depend on factors such as power, and performance.

11 thoughts on “Harley Milwaukee 8 Problems: Its Signs, Consequences and Fixing Tips”

    • Thank you for considering an upgrade! 2020 and newer models are definitely worth checking out. They often come with a range of improved features and technology that can make your ride more enjoyable. It’s always a good idea to do some research and compare different models before making a decision. You might even want to test drive a few different bikes to see which one feels the best to you. Good luck with your search!

  1. I am currently having this issue and now that I understand what is causing the problem, I will call the dealership to have it fixed. I bought the extended 3 year warranty. I hope this is covered under warranty. Does anyone know if there’s been a recall?

    • It is not possible to confirm whether there has been a recall for the specific issue you are experiencing without more information about the problem and the make and model of your Harley Davidson motorcycle. However, it is a good idea to contact your dealership and the manufacturer to inquire about any possible recalls or service bulletins that may be related to your issue. If you have purchased an extended 3-year warranty, it is also important to check the terms and conditions of the warranty to see if the issue you are experiencing is covered. Additionally, you can check the National Highway Traffic Safety Administration (NHTSA) website to see if there are any ongoing recall investigation related to your motorcycle.

  2. You also can upgrade to the screaming eagle performance oil pump/cam plate. Which I believe is even a better option, though probably a more expensive option.

  3. I have a 2018 114 Breakout, and have only 1200 miles. Does anyone know when this sumping and overheating starts milage wise ? I know long rides can induce the damage to start. The days have been 103 to 107 degrees in Austin Texas this summer and I haven’t experienced any loss of performance or power/ torque during rides except if I get stuck at a long light and it goes to single firing cylinder idle when I start up again off the green light it bogs a lil and have to pick up the rpms. But after it gets some cooler air intake it goes back to normal running.

  4. Well never had more problems with a motorcycle I own a 2022 triglide ultra
    oil consumption then clutch issues and not being able to get in neutral and now it stopped
    running for no reason it only has 3500 miles on it and they dealer said it will be a week or so till they get to it still under warrenty got a extended one what next

  5. Ich fahre eine screeming eagle ultra 117.
    Sobald der Motor heiss ist, habe ich Probleme beim Gas geben aber nur,wenn die Drehzahl unter 2300 Umdrehungen ist.
    Das ist ein Problem, wenn ich überholen will.

    Kennt jemand dieses Problem?


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