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Milwaukee 8 Problems: Too Much To Handle? Yes and No

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If you’re a motorcycle enthusiast, then you might have heard tales about the Milwaukee 8 problems that riders often face. Problems of fragile engine internals, difficulty starting, and fuel injection issues have left many questioning – is the Milwaukee 8 simply too much to handle?

On the contrary. This powerful beast, with the roar synonymous with Harley-Davidson, has its shares of pros and cons, just like any complex machinery. While issues do exist, they can be mitigated, managed, or even eliminated, providing one knows how.

Dive with us into the twists and turns of the Milwaukee 8 engine, as we debunk myths, confront realities, and examine the common problems it presents. More importantly, get ready to uncover the truth about whether or not these are truly deal-breakers. Discover what’s on the other side of the problem coin, a side often overshadowed by its counterpart. Is it all bad news, or does the solution shine brighter? Let’s find out.

How Has Harley’s Motor Engineering Developed Over Time?

Harley Davidson’s journey in motor engineering is a story of constant evolution and improvement. From their first V-twin engine in 1909 to the introduction of the Milwaukee-Eight in 2017, the company has consistently strived to enhance the riding experience for its customers.

Related:
Harley Engines by Year: The Legacy of American Motorcycling
Twin Cam vs Milwaukee 8

Here’s an example of how Harley Davidson motors have changed over time:

Infographic showing how harley davidson motors have developed and changed over time

The Milwaukee-Eight engine, introduced as a replacement for the Twin Cam engine, was developed with the goal of delivering more power, less engine vibration, and better heat management. The engine’s design includes two cylinders in a V-shape configuration and four valves per cylinder, adding up to eight valves in total – hence the name Milwaukee-Eight.

Related articles:
Harley 107 vs 114
> Harley 107 vs 114 vs 117: A Milwaukee Bound Shootout

But, Is The Milwaukee 8 Reliable?

When it comes to the reliability of the Milwaukee 8 engine, the conversation often sparks a mix of opinions among Harley-Davidson enthusiasts. Introduced in 2017, this engine was designed to offer a smoother, more powerful ride, but like any mechanical innovation, it has its quirks and challenges.

Read more: A Shootout For The Most Reliable Harley Engine (What Is It?)


Common Milwaukee 8 Problems You May Encounter

While the Milwaukee-Eight engine has been lauded for its performance, several issues have been reported over the years. These range from mechanical and transmission problems to general ones like overheating and difficulty starting. Let’s delve into these problems and explore potential solutions.

Mechanical Problems

1. Poor Crankshaft Configuration

One of the critical Milwaukee 8 problems is related to its crankshaft configuration. The crankshaft’s interaction with the twin cams at high speeds can lead to misalignment, causing the left flywheel to slide out of place due to the force exerted by the spline shaft. This displacement can then lead to the crankpin becoming misplaced, resulting in engine failure.

image showing the configuration of the milwaukee 8 engines single crankshaft design

Solution: If you suspect issues with the crankshaft, it’s best to seek professional help immediately. Early diagnosis can prevent extensive damage, and you may only need to replace the damaged part as opposed to the entire crankshaft.

2. Issue With The Harmonic Balancers

Despite being equipped with twin internal counterbalancers designed to reduce excessive vibrations, the Milwaukee-Eight engine can still produce significant vibrations at high speeds. This could be due to inherent issues with the engine, including a defective harmonic balancer and internal engine imbalance.

Solution: If you’re unable to fix this issue yourself, it’s best to take your bike to a professional mechanic. They may need to readjust the engine or replace the harmonic balancer to reduce engine vibrations.

3. Rattling Noise In The Engine

If you hear a rattling noise emanating from your engine, it could indicate that there are loose or broken parts within the engine that are grinding against each other. This can lead to further engine damage if not addressed immediately.

a look inside the head of a milwaukee 8 to show the harmonic balancers in action

Solution: If you hear strange noises coming from your engine, it’s time to see a mechanic. They’ll open up the engine, check for any broken parts, and replace them as necessary.

4. Excess Vibration From The Engine

Excessive engine vibration is another common Milwaukee 8 problem. This is often due to misaligned or low-quality internal engine components.

Solution: A mechanic can help diagnose the cause of the excessive vibration and may suggest balancing the engine or checking the engine mounts for tightness.

5. Poorly Designed Cam Chain Tensioners

The Milwaukee-Eight engine’s plastic cam chain tensioners can wear out quickly, leading to overheating, improper oil supply and engine failure.

Solution: Replacing worn-out cam chain tensioners is the best solution to this problem. Ensure you replace them with high-quality tensioners for better engine performance.

Keep reading:
> Best Battery for Harley Davidson Motorcycles
> Best Spark Plugs for Harley Davidsons

Is It The Same as The Twin Cam Motor Problems?

While some Milwaukee 8 problems may seem similar to those reported with the Twin Cam engine, it’s important to note that these are two different engines with distinct designs and issues. For instance, the Twin Cam engine was notorious for its cam chain tensioner problems, while the Milwaukee-Eight engine faces issues like poor crankshaft configuration and harmonic balancer defects.

Read more about this: Harley Twin Cam Problems

Transmission Problems

1. Clutch Failure

One of the common Milwaukee 8 problems is clutch failure, often caused by oil leaks. This can lead to stiff gear shifting and a clunky sound when shifting gears.

Solution: Inspect the engine for oil leaks and replace worn-out oil gaskets. Regular clutch assembly and cable inspection can also help identify and address any clutch-related issues early.

Related article: Harley Hydraulic Clutch Problems

2. What’s The Issue With The Gear Oil?

Low gear oil levels can make it difficult to shift between gears, putting more pressure on the transmission and engine.

Solution: Regularly check your gear oil level and follow a strict maintenance schedule. If you notice any signs of low gear oil levels, have your motorcycle inspected by a professional mechanic.

Read next: Harley EITMS Problems


More General Milwaukee 8 Problems

Frequently Overheating

Despite the Milwaukee-Eight engine’s advanced heat management system, some riders have reported overheating issues. This can be due to a clogged or faulty radiator that impedes proper airflow, leading to heat build-up.

Solution: Regular inspections and cleaning of the radiator can help maintain optimal cooling performance. If the radiator is severely damaged, it may need to be replaced.

Issue With Oil Sumping

Oil sumping, where engine oil accumulates in the gear case and crankcase, is a common issue with the Milwaukee-Eight engine. This reduces the oil level in the engine and affects its performance.

Solution: Regular oil level checks and engine inspections can help identify oil sumping early. If it’s a recurring problem, replacing the faulty oil pump may be necessary.

Keep reading:
> Who Makes Harleys Oil and Filters
> Who Manufactures Harley Davidson Spark Plugs

Engine Oil Will Trap Air

Air entrapment in the engine oil, also known as oil aeration, can occur due to wet sumping. This leads to increased stress on engine parts and faster wear and tear.

Solution: To prevent air from entering the oil supply lines, check for any blockages and replace any faulty parts. Fixing the wet sumping issue can also help prevent oil aeration.

Related reads:
Harley M8 Oil Capacity Guide (All Sizes Explained)
Harley M8 Primary Oil Capacity (All Engine Sizes Explained)
The Best Oil for M8 Harley Engines Gets Revealed (Complete)

Inconsistent Acceleration

Inconsistent acceleration can be a symptom of several Milwaukee 8 problems, including increased oil pressure, harmonic balancer issues, and engine imbalance.

Solution: Regular engine inspections and maintenance can help you identify and address these issues. You may need to replace certain parts or adjust the engine to improve acceleration. Some owners opt for a Milwaukee 8 specific tuner.

Read more: Harley 103 vs 107

Were There Any Recalls With The Milwaukee Eight Series?

Yes, there were recalls with the Milwaukee Eight series engines. In particular, a recall for the oil pump was most notable. Specifically, riders experienced premature wear on vital engine internals because the oil pump was not providing adequate lubrication. To counteract this, Harley addressed the issue quickly by offering replacement of the oil pump, but also improved on the oil pump design for later models.

Related: Milwaukee 8 Oil Pump Recall


What Does The Community Say About The Milwaukee 8?

The Milwaukee-Eight engine has received mixed reviews from the motorcycle community. While some riders praise its superior performance and smooth power delivery, others have raised concerns about the various mechanical, transmission, and general issues it’s prone to.

What Are The Most Common Milwaukee 8 Problems?

The most common Milwaukee 8 problems include issues with the crankshaft configuration, harmonic balancers, rattling engine noise, excessive engine vibration, poorly designed cam chain tensioners, clutch failure, gear oil issues, overheating, oil sumping, air entrapment in engine oil, and inconsistent acceleration.

What Can I Do To Prevent Milwaukee 8 Problems?

Regular maintenance and inspection of your motorcycle can go a long way in preventing Milwaukee 8 problems. It’s also important to address any issues as soon as they arise to prevent further damage.

Keep reading: What Year Harleys To Avoid


In Conclusion

While the Milwaukee-Eight engine has its share of problems, it’s also important to remember that it’s a powerful and high-performance engine that many riders swear by. If you’re experiencing any of the Milwaukee 8 problems discussed in this article, it’s always best to consult with a professional mechanic or a Harley Davidson dealer. Regular maintenance and timely repairs can help keep your Milwaukee-Eight engine running smoothly for years to come.