Look, we all know that rolling on a Harley is like joining an elite club. It’s all about that legendary roar, the open road, and the instant cred you get from sporting that iconic bar and shield.
But let’s keep it real, not every Harley model year is a shining star in that chrome-studded sky.
Some Twin Cam years? Yikes, they’re more like black holes of disappointment.
So, if you’re looking to ride hard without dealing with the worst kinda mechanical headaches, you’re in the right place.
Buckle up, because we’re about to dive into the Harley Twin Cam years you should steer clear of. Trust me, you’ll thank me later.
Worst Harley Twin Cam Years – Avoid These!
While the Twin Cam engine is popular among riders, it has its fair share of issues that can result in some costly repairs for ya, and even engine failure.
Here are the Harley Twin Cam years we recommend that you avoid:
- 1999-2002: These years are notorious for a design flaw involving the cam tension follower that can cause the engine to fail prematurely. While some riders have been able to avoid this issue by replacing the cam components, it’s still a risk you’ll want to consider before buying a bike from this era.
- 2003-2006: In an effort to cut production costs, Harley Davidson switched from bulletproof Timken cam bearings to pressed-in roller bearings and a pressed crankshaft. This change has led to issues with the bearings wearing out prematurely and causing engine failure.
- 2005: This year is considered by many to be the worst for the Twin Cam engine. The crank and heads are known to be problematic, and many riders have experienced untimely and horrible engine failure. If you’re considering a bike from this year, be sure to have it thoroughly inspected by a mechanic before making a purchase.
While these are definitely the worst Harley Twin Cam years to avoid, it’s important for you to know that all Twin Cam engines have the potential for issues.
One thing to keep in mind once you get a bike with a twin cam engine is that you gotta keep up with regular maintenance for it to keep your bike running smoothly for years to come.
Engine Design and Issues
Now let’s take a closer look at the Twin Cam engine, Evolution engine, and Milwaukee-Eight engine to get familiar with their designs and issues.
Twin Cam Engines
The Twin Cam engine was introduced in 1998 and quickly became a popular choice among Harley riders.
However, there are a few years of the Twin Cam engine models that you may want to avoid due to engine issues.
Specifically, the cam chain tensioners in Twin Cam engines from 1999 to 2006 have a history of failing on their owners, which can lead to catastrophic engine failure.
Evolution Engine
The Evolution engine was introduced in 1984 and was used in Harley-Davidson motorcycles until 1999.
That’s when it was replaced by the Twin Cam engine.
The Evolution engine is known for its durability and reliability, but it also has a few issues that you should be aware of.
One common issue with the Evolution engine is oil leaks, which is caused by things like worn gaskets or seals.
Milwaukee-Eight Engine
The Milwaukee-Eight engine was introduced in 2016 and is the newest engine option from Harley-Davidson.
This engine is designed to be more efficient and powerful than previous engine options.
The Milwaukee-Eight engine has a few improvements over the Twin Cam engine, such as a redesigned cam system that eliminates the need for cam chain tensioners.
However, it is still a relatively new engine, so there may be issues that arise as more riders put miles on their motorcycles.
Cam Chain Tensioner Problems
The number one thing you gotta be aware of is the cam chain tensioner problems that have plagued some models.
The cam chain tensioner is what’s directly responsible for maintaining that proper tension on the cam chain, which is essential for the engine to function properly.
Unfortunately, some Twin Cam engines have experienced cam chain tensioner failures, which can lead to serious engine damage.
The problem with the cam chain tensioner is most commonly found in Twin Cam engines produced between 1999 and 2006.
The hydraulic cam chain tensioner used in these models was prone to failure, which could cause the plastic tensioner shoes to break apart and circulate through the oil system.
This can cause damage to other engine components and lead to catastrophic engine failure.
To address this issue, some Harley owners have opted to upgrade their cam chain tensioner system with aftermarket parts.
One popular upgrade is the spring tensioner, which can provide more reliable and consistent tension on the cam chain.
Another option is to switch to a gear-driven cam system, which eliminates the need for a cam chain altogether.
If you own a Harley Twin Cam motorcycle that is prone to cam chain tensioner problems, it is important to take proactive measures to prevent engine damage.
Regular maintenance, including frequent oil changes and inspections of the cam chain tensioner, can help identify potential issues before they become serious problems.
Of course, upgrading to a more reliable cam chain tensioner system can provide peace of mind and prevent costly engine repairs down the road.
Harley-Davidson Models
Assuming that you’re shopping for a new Harley-Davidson motorcycle, we’ve got the most popular Harley-Davidson models for ya and the years to avoid.
Dyna
The Dyna model was first introduced in 1991 and was a popular choice for riders looking for a more aggressive ride.
However, there are a few years that you should avoid if you’re considering a Dyna.
The 2006 Dyna model had a problem with the fuel tank that could cause the bike to stall.
The 2007 Dyna model had a similar problem, as well as a problem with the transmission that could cause the bike to slip out of gear.
Sportster
The Sportster is one of Harley-Davidson’s most popular models, but there are a few years that you should avoid.
The 2001 Sportster model had a problem with the cam chain tensioners that could cause the engine to fail.
The 2007 Sportster model had a similar problem, as well as a problem with the clutch that could cause the bike to stall.
Electra Glide
The Electra Glide is a popular touring bike, but there are a few years that you should avoid if you’re considering this model.
The 2014 Electra Glide model had a problem with the transmission that could cause the bike to slip out of gear.
The 2015 Electra Glide model had a similar problem, as well as a problem with the fuel system that could cause the bike to stall.
Oil Pump and Pressure Issues
If you own a Harley Twin Cam, you might have experienced oil pump and pressure issues.
The Twin Cam engine requires a strong and consistent flow of oil to prevent damage, but some riders have reported issues with oil pressure and flow.
This can end up leading to some serious problems if left untreated.
One common issue is oil leaks, which can be caused by a faulty oil pump.
If the oil pump fails or malfunctions, it can cause low oil pressure and oil leaks. This results in engine damage if not addressed promptly.
Another issue is clogged oil passages, which can occur if the engine oil is not changed regularly.
Over time, what ends up happing is that the engine oil becomes contaminated with dirt, debris, and metal shavings.
These contaminants can block the oil passages and reduce oil flow, and that leads to low oil pressure and engine damage.
To prevent oil pump and pressure issues, you really gotta change the engine oil and oil filter regularly.
You should also use high-quality engine oil that meets the manufacturer’s specifications.
If you notice any signs of low oil pressure or oil leaks, you should have your bike inspected by a qualified mechanic.
Engine Runout and Bearings
Another thing that you’ll wanna be aware of is the potential issues with engine runout and bearings.
Runout is when the crankshaft wobbles or moves out of position, which can cause significant damage to the engine over time.
Several things can cause this, like high crank runout, which was a significant issue with the Twin Cam engines produced between 2003 and 2006.
During this period, Harley-Davidson decided to cut production costs by replacing the bulletproof Timken cam bearings with pressed-in roller bearings and a pressed crankshaft.
However, this decision led to runout or wobbling issues in the crank assembly, causing damage to the oil pump, cams, and parts of the engine block.
This problem was so severe that it led to a class-action lawsuit against Harley-Davidson, which the company eventually settled.
If you’re considering a Harley-Davidson motorcycle with a Twin Cam engine produced between 2003 and 2006, you’ll wanna pay close attention to the engine’s condition and look for signs of runout.
Some common symptoms of runout include excessive engine noise, vibration, and oil leaks.
If you notice any of these issues, it’s best to have the engine check out by a qualified mechanic that you trust so you can determine the extent of the problem and whether it can be repaired.
Harley-Davidson Mechanical Issues
You should know about some of the most common mechanical issues that you may encounter with a Harley-Davidson Twin Cam engine.
One of the most common issues with the Twin Cam engine is gearbox problems. Many riders have reported issues with the gearbox, including difficulty shifting and gear slippage.
Things like worn gears, damaged shift forks, and a faulty clutch all can cause this problem.
Another issue that you may encounter with a Twin Cam engine is piston recoil issues.
This can cause smoke blowing from the exhaust and a loss of power. The problem is caused by a faulty piston design that can cause the piston to seize in the cylinder.
Hydraulic lifters are also a common problem with Twin Cam engines. These lifters can become worn or damaged over time, causing excessive valve noise and poor engine performance.
This can be a costly repair, as the lifters are located deep within the engine and can be difficult to access.
If you’re looking at a Twin Cam from the late 1990s or early 2000s, you should be aware that the rear cam bearing may need to be changed out.
This is a known issue with these engines, and can cause excessive engine noise and poor performance.
Cam tensioners are another common issue with Twin Cam engines.
These tensioners can become worn or damaged over time, causing excessive engine noise and poor performance.
This can be a costly repair, as the tensioners are located deep within the engine and can be difficult to access.
Head problems can also be an issue with Twin Cam engines.
These problems can include cracked or damaged cylinder heads, which can cause oil leaks and poor engine performance. In some cases, the entire head may need to be replaced.
Vibrations are another common issue with Twin Cam engines.
These vibrations can be caused by a number of factors, including design flaws and rubber-mounting issues.
In some cases, these vibrations can be so dang severe that they can actually cause real damage to the engine or other components.
Dragging brakes can also be a problem with Twin Cam engines. Things like worn brake pads, damaged brake calipers, and a faulty brake master cylinder all can cause this problem.
Finally, transmission issues can also be a problem with Twin Cam engines.
These issues can include difficulty shifting, gear slippage, and excessive noise. In some cases, the entire transmission may need to be replaced.
Used Harley-Davidson Considerations
Let’s say you’re in the market for a used Harley-Davidson. With that in mind, there are a few things you should consider to ensure you’re making a wise investment.
First and foremost, do your research. Not all Harley Twin Cam engines are created equal, and some model years have known issues (like what we’ve covered above) that can lead to some costly repairs down the road.
As we discussed earlier, you’ll wanna steer clear of the 1999-2002 models due to camshaft chain tensioner failures, as well as the 2003-2006 models with high crank runout and pressed-in roller bearings.
When considering a used Harley, it’s also important to take into account the bike’s overall condition.
Look for signs of wear and tear, such as scratches, dents, and rust, as these can indicate a lack of proper maintenance.
Additionally, be sure to check the mileage and service records to get a better idea of the bike’s history.
Another factor to consider is the bike’s resale value. Some Harley models hold their value better than others, so it’s important to do your research and choose a model that is in demand.
As a general rule, the more popular the model, the better its resale value.
Finally, keep in mind that not all Harley models are created equal when it comes to sales.
Some models simply don’t sell as well as others, which can make them more difficult to resell down the line. Be sure to take this into account when choosing a used Harley-Davidson.
Engine Power and Efficiency
When it comes to the Harley Twin Cam engine, power and efficiency are two of the most important factors to consider.
The Twin Cam engine was designed to provide riders with a balance of power and fuel efficiency, making it a great choice for those who want a reliable and powerful engine.
The Twin Cam engine is available in different stages, with each stage offering different levels of power and performance.
Stage 2 and Stage 3 upgrades are available for those who want to take their engine’s power to the next level.
These upgrades can significantly increase the engine’s horsepower and torque, but they can also impact fuel efficiency.
In terms of fuel efficiency, the Twin Cam engine is designed to provide riders with a balance between power and fuel economy.
The engine is equipped with a fuel injection system that helps to optimize fuel consumption, making it more efficient than older carbureted engines.
It’s worth noting that some Twin Cam engine models have design flaws that can impact engine performance and reliability.
For example, the cam tension follower flaw in the 1999-2002 models can cause engine failure if not addressed.
Additionally, the 2003-2006 models have a high crank runout issue that can also impact engine performance.
Reliability of Harley Twin Cam Engines
When it comes to Harley Twin Cam engines, there are certain years that are known to be more reliable than others.
While the Twin Cam engine has been industry-transforming, it’s not perfect. Here are some things to keep in mind when considering the reliability of Harley Twin Cam engines.
It’s important to note that Harley Twin Cam engines are generally considered to be very reliable.
They are known for their durability and long lifespan. However, there are certain years that are more prone to issues than others.
One of the main issues with Harley Twin Cam engines is the cam bearings.
In 2003, Harley-Davidson made a cost-cutting decision to switch from the bulletproof Timken cam bearings to pressed-in roller bearings.
This change has been known to cause issues with the cam bearings, and is one of the reasons why the 2003-2006 Twin Cam engines are often avoided.
Another issue to be aware of is the crankshaft. The 2005 Twin Cam engines are known to have a bad crank design, which can cause issues with the engine’s performance.
The crankshaft design was improved in later years, but it’s still something to keep in mind if you’re considering a Twin Cam engine.
Overall, while there are certain years of Harley Twin Cam engines that are more prone to issues than others, they are generally considered to be very reliable engines.
Final Word
If you’re looking for a reliable engine, the Harley Twin Cam is a great option overall.
You just gotta be aware of the potential issues with certain years, so that you don’t end up with a lemon.
And make sure that you properly maintain and care for your engine to ensure it lasts for years to come.