12 Dreaded Harley 107 Problems: Exhaustive Overview (2024)

For the adventurer at heart, a Harley Davidson isn’t just a motorcycle; it’s a lifestyle. However, even the most reliable road companion can sometimes pose challenges.

Today, we’re navigating the most talked-about issue in every biking forum worldwide: the infamous Harley 107 problems. Through the roar of the exhaust and the call of the open road, there can be a few hiccups that might dampen your journey.

Let’s rev up our engines and ride down this troubleshooting path together for an exhaustive overview of the 12 dreaded Harley 107 challenges that have swept bikers off their seats in 2023. Buckle up for an informative and adrenaline-fueled ride ahead!

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Most Common Harley 107 Problems

harley 107 problems infographic to show the common problems associated with the engine

The Harley 107, despite being a modern and high-performance engine, has been known to exhibit a variety of problems. From oil-related irregularities to issues with various components, these problems can be quite a nuisance for riders. However, with proper knowledge and preventative measures, these issues can be mitigated. Here is a comprehensive list of the most common Harley 107 problems:

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1. Inconsistent Oil Pump Performance

One of the most frequently reported issues with the Harley 107 engine is ongoing oil pump issues. The oil pump plays a crucial role in ensuring that the engine parts are adequately lubricated, reducing friction and heat. However, these oil pump issues, can lead to oil leaks or inadequate lubrication, causing the engine parts to grind against each other. This issue is often associated with low-quality cam chain tensioners, which can block the oil supply from the oil pump, disrupting the oil flow to the engine.

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2. Aeration of The Oil

Oil aeration, or the presence of air bubbles in the engine oil, is another common issue with the Harley 107 engine. This problem can be caused by aggressive riding habits, inadequate oil supply, or high oil temperatures. Oil aeration can lead to diminished engine performance, increased oil consumption, reduced oil pressure, and potential damage to vital engine components. It can also make it difficult to measure the oil level accurately, making maintenance a challenge.

3. Wet Sumping

Wet sumping is a condition wherein oil accumulates in the engine crankcase when the motorcycle is at rest or parked for an extended period. This issue typically occurs due to the design and operation of the oil pump and check valve system. If unchecked, wet sumping can lead to increased pressure, oil foaming, lubrication inefficiency, oil leakage, and crankcase breathing issues.

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an example of an oil leak developing on a harley davidson 107ci motor

What Is A Wet Sump vs Dry Sump

A wet sump system is where the oil resides in the oil pan under the engine, while a dry sump system uses a separate tank to store the oil. The Harley 107 engine uses a wet sump system, which, while simpler and less expensive, is more prone to issues like wet sumping.

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4. Burning Engine Oil

Burning engine oil is a problem that is often associated with excessive oil consumption. This issue can result from oil seeping past the rings, valve guides, and valve seals. Over time, the excessive oil can build up in the crankcase, impairing the engine’s performance and causing smoke clouds to emerge from the exhaust pipes.

5. Cam Chain Tensioner Failure

Cam chain tensioner failure is a common issue in Harley 107 engines. The problem lies in the design of the cam chain system, which uses plastic shoes that wear out over time. Despite Harley Davidson introducing a new hydraulic tensioning system in later models, the issue persisted. When these plastic components fail, they can block the oil supply, leading to oil pump issues and, eventually, engine failure.

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What’s The Harley Twin Cam Problem?

The Harley Twin Cam engine, predecessor to the Harley 107, was known for its issues with cam chain tensioners. The tensioners in these Harley engines were made of a material that could wear out and disintegrate, leading to metal-to-metal contact and engine failure. This issue has been mitigated in the Harley 107 engines with improved tensioning systems, but problems still persist.

6. Defective Crankshafts (Engine Knocking)

A defective crankshaft is another common issue in Harley 107 engines. This problem often manifests as engine knocking, which is caused by excessive vibrations and could indicate a flawed crankshaft. If the crankpin shifts or bends, it can lead to engine failure. In some cases, the rear spline shaft can push down on the left flywheel, causing misalignment and leading to engine failure.

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7. Overheating Engine

Harley 107 engines are known to have overheating issues, which can be exacerbated by oil pump problems. The factory-assembled oil pump in these engines can only accommodate a Stage 1 kit, and attempting to do stage upgrades beyond this can result in engine overheating. Therefore, if you plan on performing any significant upgrades, it is recommended to upgrade the oil pump as well.

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8. Difficulty Starting

Difficulty starting, especially in cold temperatures, is a common problem in Harley 107 engines. This issue can result from inadequate fuel atomization, improper fuel mixture, or insufficient spark during ignition. However, oil-related issues can also exacerbate this problem, making it challenging for the engine to start in cold conditions.

More General Complaints

Aside from the problems mentioned above, Harley 107 engines have also been known to have other general complaints. These include:

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9. Issue With The Exhaust System

Many Harley 107 owners have reported issues with the exhaust system, such as leaks or excessive noise. These problems can often be caused by a build-up of carbon in the exhaust system, or a failure of the muffler packing.

showing the discoloration on the exhaust pipe of a bike with harleys 107 engine

10. Excessive Engine Vibration

Excessive engine vibration is a common issue reported by Harley 107 owners. This can be caused by a number of factors, including engine imbalance, loose motor mounts, and a defective harmonic balancer.

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11. Fuel System Related Issues

The Harley 107 engine can also suffer from fuel system problems. These can range from simple issues like a dirty fuel filter to more serious issues like a faulty fuel injector.

12. Cooling System Related Issues

Cooling system issues, such as overheating or radiator leaks, have also been reported by many Harley 107 owners. These issues are often caused by a build-up of sediment in the radiator, which can be due to engine coolant breakdown or improper maintenance.

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In conclusion, while the Harley 107 engine is known for its power and performance, it is not without its share of problems. However, with proper knowledge and regular maintenance, these issues can be effectively managed, ensuring a smooth and enjoyable ride.

Frequently Asked Questions

Here are some frequently asked questions about Harley 107 problems:

What are some of the best year motors for Harley 107 engines?

The best year motors for Harley 107 engines are often considered to be the ones produced from 2017 onwards, as these models have benefited from several design improvements and updates.

Are there any Harley years to avoid?

While the 2007 and 2008 models of Harley Davidson motorcycles are often cited as years to avoid due to numerous engine problems, it is essential to note that issues can occur in any model year. Regular maintenance and proper care can help mitigate these problems.

What is considered one of Harley’s best engines?

The Harley Twin Cam 103 engine is often considered one of the best Harley engines due to its impressive power output and reliability.

Is the Harley 107 a Twin Cam?

No, the Harley 107 is not a Twin Cam. It is part of the Milwaukee-Eight series, which succeeded the Twin Cam engines. The 107 refers to the engine’s displacement in cubic inches.

How Many CC is a 107 Harley Engine?

The 107 Harley engine has a displacement of approximately 1,746 cubic centimeters (cc). This size is a result of converting its 107 cubic inches of displacement into the metric system.

What Year Did Harley Start the 107 Engine?

Harley-Davidson introduced the 107 engine in 2017 as part of their Milwaukee-Eight series. This launch marked a significant update in their engine line-up, replacing the previous Twin Cam models.

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