How Many Miles Will A Harley 103 Last? Some Facts And Durability

Harley Davidson engines are legendary. They will work much longer than many other parts of a bike. We know cases when people bought frames from scrapyards, installed their engines with more than 120 000 miles on the clock, and continued riding their bikes for years. Of course, the majority of bike engines just don't live so many years to hit this mileage.

On average, an American motorbike owner will ride the bike for 5 000 miles a year. Simple math shows that in ten years you will only make 50 000 miles which is not a lot for any modern engine. Today, we'll be talking about the 103 Harley Davidson engines which is a living legend. This is one of the most reliable engines in the motorcycle world.

Here's what we will discuss in this article:

1. Some specs of the 103 engine you would want to know.
2. The 103 HD engine longevity - how many miles can it last?
3. Main problems you can face with a 103 engine in your bike.
4. Repair problems and also ways to make your bike engine live longer.

Let's get started!

What is a 103 Harley Davidson engine?

"103" in the name of this engine means 103 cubic inches or 1690 cc displacement. Look, it's just like in an average compact car. The big displacement and the twin-cam construction are the main advantages of these engines. They are very reliable and long-lasting just because they don't experience overloads. That's why they don't overheat and live much longer than many other bike engines.

Also, thanks to their big displacement, you will not need to rev up the engine hard. It will work within the comfortable RPM range and will not wear intensively because of high rotations. This engine is constructed with longevity in mind, and it's very important.

Here are some specifications you may need to know:

1. This is a classic Twin Cam engine that was first introduced in 2010. In 2017 the company stopped producing the Twin Cam series including the 103 engine, but it still works hard in many motorcycles by Harley Davidson.
2. 100 pound-feet of torque allows for great acceleration. The interesting thing is that the torque is available at 3500 RPM at its maximum, so revving up doesn't make any sense in these engines.
3. The electronic fuel injection system seems to work well and it doesn't bother you much with any problems. But you should know that when it starts failing, you will have to spend a lot of money on the repair.
4. The engine was built to fix the mistakes that were made in previous Twin Cam engines. So, this engine doesn't have many minor problems that many other Twin Cam units have.

A lot of owners use this engine for different performance upgrades. They tend to tune the engine and get much more power than the stock 103 engine can provide. But we don't recommend tuning because it will change the way your Twin Cam unit works and will sharply reduce the longevity of the engine.

You will not have problems with parts for repairing this unit. Also, you will not need to repair it very often because the construction is extremely reliable. Unfortunately, we don't have much information on servicing the engine, so you will most likely have to go to the dealer for complicated repair procedures.

How many miles will your HD 103 engine last?

The 103 engines are the golden middle in Harleys. These engines aren't too big, they offer good gas mileage (47-50 MPG), and they ensure wonderful acceleration and top speed. The average mileage of the 103 engines is about 150 000 miles. You need to service it thoroughly to ensure that it won't break sooner than that.

Servicing and maintaining the Harley Davidson engine is a crucial factor that determines the mileage of the unit. Be careful when you choose parts and fluids for servicing the engine. Once you use bad oil, you can kill the piston rings, valve seals, pistons, and even the engine block.

Here are some factors that will ensure really great longevity of the 103 HD engine:

• good oil - the viscosity and chemical components of the chosen oil should be just the same as the producer recommends;
• RPMs when riding - don't rev up your engine, but also don't ride on low RPM level, choose optimal ways of riding;
• mileage a year - you will be able to ride your bike for more miles if you make a lot of miles yearly;
• regular maintenance - if you don't change the oil when recommended, don't count on the longevity of your 103 engine;
• repair - if you see black smoke or hear some noise from the engine, go to the repair shop and deal with the problem immediately.

A lot of Harley Davidson engines are killed just because the owner of the bike doesn't consult mechanics when something goes wrong. We don't recommend repairing this engine in your own garage because the construction is not that simple. We predict that you will still need to go to the service station but with a bike that was taken apart.

Overheating is one of the main reasons why your 103 Harley Davidson engine may fail. These engines don't like high RPMs, they hate continuous riding sessions without a stop during hot weather. These bike engines need your attention so that they could last for 150 000 miles. But they obviously have the potential to last that long.

Problems and breakdowns you may face

The 103 engines are very technological in comparison with other bike engines of the latest decade. These units will not bother you with minor problems, but they may fail if you don't care about the manufacturer's requirements.

But these engines obviously have some problems. You may know that the Twin Cam engine series was discontinued because of EPA requirements. So, we can presume that your 103 engine is not very eco-friendly. This is the first problem that doesn't touch on longevity or reliability, but it still may be a deciding factor for someone.

Here are some problems you may face with this engine:

1. Vibration. Excessive vibration is actually the common problem of all Twin Cam engines. You will not be able to do anything with this. We just recommend stopping every hour when you ride your Harley on long-distance journeys. Because you have to let your body rest from vibration.
2. Sound. The sound may seem really cool once you try to accelerate on your bike. But over time, it starts being annoying. You will not be able to do anything with this sound, just try to accelerate not so sharp to reduce the noise contamination around you. Especially, at night.
3. Leaking oil. Some oil leaks are absolutely OK for motorcycle engines. But your Harley 103 engine will probably be the leader in this sphere. It will leak regularly and you will have to pay for repairs every single time.
4. Cooling. The cooling system is not very efficient. We would say it needs some tuning. Overheating is a deadly danger for this bike and the heating is not good enough to prevent overheating, especially when you are riding on high-speed highways.
5. Fuel injection issues. Well, the injection system is impressively good, but at around 50 000 miles it starts causing some problems. And the biggest problem is that repairing this complicated fuel injection system is not very easy.
6. Oil consumption. These engines burn some oil when they work at high RPM. If you don't check the oil level regularly, you can miss the point when you need to add some oil. And this will lead to problems with pistons and a cylinder block.

As you see, these engines can also be problematic if you don't care about them as you should. Especially, they will show bad problems when you forget about oil change intervals or just don't add oil when the level is below the minimal mark.

Though, if you care about the engine, it will go around 150 000 miles which is more than enough for your bike. We don't think you will ride your Harley for 30 years. It's more than possible that you will want to buy something new during this time.

Final words

If you look at an average motorcycle engine, you will see that the longevity of such units is around 80 000 miles. This is the average figure for all bikes. Harley Davidson stands much higher than average. The longevity of the 103 Twin Cam engine is around 150 000 miles. What's more, this engine will not bother you much with possible problems within this mileage.

Yes, you will still need to service and sometimes repair this engine, but it's still a good unit to buy. Unfortunately, now you can only buy a used bike with a 103 engine because these units were discontinued by the company.