Harley Davidson 103 Engine Problems And Solutions

Harley Davidson 103 Engine Problems 

We are well aware of your love for the Harley Davidson bike. Who doesn’t love a Harley Davidson motorcycle? The look, unique style, and customization are the things that boost the confidence of a biker and Harley Davidson got them all. But as a loyal admirer of this brand, you should also know there is an issue that occurs often in a Harley Davidson bike and the problem is Twin Cam engines.

There are two types of twin-cam engine problems in Harley Davidson. Here we will discuss the problems first and then provide a solution for them as well in this article. Read a comprehensive guide on Cam for Stock Twin Cam 88.

Harley Davidson Twin Cam 103 Engine Problems 

Again, we know how much you love Harley Davidson twin cam motorcycles. However, you still need to know what you are buying and be aware of exactly what you are buying so that there are no surprise expenses once you start riding the motorcycle.

Twin Cam engines have many flaws. Enough potential problems to alarm you and make you think twice before buying one.

Probably the biggest problem with the Harley Davidson Twin Cam engine is the design aspect of the cam chain. The design itself is poorly engineered. It uses plastic “overlapping” pads on the chains of the cam which can and eventually will wear out when the time is due.

With its completely latest hydraulic tensioning process, this problem still remains and is not an enduring solution to this problem.

Now, what exactly is the issue on this topic? Take that into your consideration, the engine of the Twin Cam uses plastic clogs on the chains of the camshaft.

Whenever these clogs rub against each other, they eventually wear out due to the friction and constant contact between the two rubber shoes. In some extreme cases, there will be a contact of metal to metal sooner or later and the interaction here causes metal chips and can (or will) lead to dangerous and deadly engine failures.

Harley Davidson 103 Cubic Inch Engine Problems 

In addition to the inclusion of the double camshaft, some details were refined, such as the timing chain, the combustion chambers, the gearbox was coupled directly to the crankcase, the oil pump was retouched and the cooling was improved, increasing the finning of the cylinders and including a spray that sprays oil at the base of the pistons.

The latter solution was used (and discarded) on Suzuki’s SACS engines in the early eighties. These engines were introduced in the version of 88 cubic inches (about 1450 cc) to introduce later, in 2007, a version of 96 cubic inches (1584 cc) have also come to develop a couple of kits that leave the displacement at 103 and 110 cubic inches (1690 and 1800 cc respectively).

On the downside, it should be noted that this last variation has made the Twin Cam engines vibrate even more than the previous ones, so that until 2000 could not be mounted on Softail chassis.

In a display of skill in Harley got down to work and developed a new 88-inch engine with a double balancer shaft driven by a chain that almost does not vibrate. Immediately the most purists of the brand put the cry in the sky because a Harley engine must necessarily vibrate.

In 105 years of history, Harley Davidson has developed only six engines, all starting from the same original base of 1929, and has continued to stay on the crest of the wave, although the wave is very special and oriented exclusively to the faithful followers of the brand.

In this period curiosities have also appeared, such as the V-Rod racing engine or the two-stroke racing engine of the eighties, but they have always remained faithful to their designs. Partly to maintain their image and partly pressured by the users themselves, reluctant to change anything in their legendary bikes. Harley Davidson is a way of life that can be felt or not, but it is unquestionably authentic.

Harley Davidson 103 Engine Problems Solutions

Harley Davidson Twin Cam 103 Engine Problem Solution

Like all other bike problems, this particular one also has a solution by which you can tackle this issue when your bike shows symptoms.

Firstly, you can directly combat this problem by using different gear systems on your Harley Davidson bike.

A good number of experts suggest replacing the gear system to resolve this issue once and for all. You won’t have to worry about your motorcycle engine anymore and it will also provide a durable lifetime to the engine. 

Sometimes twin cam engine issues appear because of using low-quality oil. Therefore, if your engine is just showing the symptoms recently, then you better try changing your oil with a better one.

It will certainly increase the performance of the engine and reduce the chance of wearing out and destruction of the engine. 

Finally, an oil cooler that has an assisting fan can be a great solution for your Harley Davidson twin cam engine problems. This one is an effective solution and it can certainly provide the right aid to the engine by ensuring a constant flow of cooling air. It will help the engine to cool down and reduce the exhausting of the plastic materials inside the engine. 

Harley Davidson 103 Cubic Inch Engine Problem Solution 

It seemed that Harley Davidson was finally going to manufacture a modern engine with the Twin Cam designation, perhaps based on the architecture of the V-Rod engine, but this would be like Ducati making pneumatically driven engines instead of the Desmodromic.

In the end, at the end of 1998, they presented the Twin Cam engine that would be installed in the 1999 models, which was nothing more than a new version of the well-known 45º air-cooled V-frame engine with overhead valves operated by pushers.

Where did the improvement of this model lie? Well, simply because it incorporated a double camshaft at the end of the crankshaft. Hence its name Twin Cam (Double Camshaft).

In this case, the need for a new model was not to replace the successful Evolution but to protect with patents all the development carried out both by Harley and by some subsidiary companies.

By an administrative error, the Evo engine was unprotected and could be cloned by any other company without any problem, so they had to get down to work to correct this situation.

Is the Harley 103 a Good Engine? 

Before each ride, check the oil level, normally this is done on a hot engine, but you will quickly get used to it and get used to it, to check it on a cold engine, and at rest, it is easier. Know that a Twin air, by its design, consumes oil and this is normal. The parent company estimates that it is normal to consume 1 liter every 1000 kilometers. This consumption varies according to the routes, urban routes, or your driving. Make the level with Semi Synthesis 20w50 oil for Turbo Diesel, especially do not exceed the maximum limit, it is better to have less than more.

Harley Davidson 103 Engine Specs

Here we are discussing all the Harley Davidson 103 engine specifications as follows: 

1. THE BRAKING: Until the arrival of the double piston calipers (the year 2000), the Harley-Davidson which was conceived for the USA, had systems that had only the name of “Brake”. In reality, they were long term retarders. You had to anticipate the obstacle and have a certain science of avoidance. Since the advent of systems worthy of the name, sometimes doubled with double discs at the front, this problem is no longer present. But finally, all 1340 were equipped with these retarders.

2. SEALS OF PUSHBUTTER: It was usual to have oil leaks at the level of the seals of pushers. The seals put at the time were “light”, the vibrations of the Big-Twin, and the pressure of oil at this place there, were right of these seals, and one found oneself with oozing, it was a Harley you will say to me!…

3. BASE GASKET: A great classic of 1340, with leaks at the level of the base gasket of the rear cylinder 1993 until 1999 and porosity of the engine crankcase except for the Harley models 1984 and 1985 with box 4.

4. REGULATOR: Repeated failures of the regulator which destroyed the battery. Overconsumption of batteries due to vibrations and heat of the oil pan on the Softails 1340 etc. On Sportsters (before 1991), the battery holder welded to the oil tank can be broken due to vibrations. With the Twin-Cam range, this concern is no longer present.

5. INJECTION SYSTEM: On the Harley 1995-2000 with Marelli injection, which is not true anymore since the 2001 and following vintages with the DELPHI management module. Some irregularities of functioning due to micro leaks had been reported. This injection system designed by Magnetti-Marelli was not very sensitive to low gas dosage, which caused variations in engine speed at a constant speed. On the other hand, this injection system was so rudimentary, with only one sensor that it never failed.

6. MISCELLANEOUS LEAKAGES: the spinnaker seals sometimes did not exceed 15,000 km. In 1340 there were often oil leaks at the level of the cylinder head gaskets, and seepage at the level of the primary crankcase, but it was due to the use of paper gaskets. Since then, with the reinforced gaskets, the problem is solved. 

7. THE DIAPHRAGM: The diaphragm clutch on the Big Twins of the 1980s to 1990s with a 5-speed gearbox was a problem, but the 4-speed gearboxes with springs did not have any particular problem. The clutch bell on the Sportster 883 and 1200 with the 4-speed gearbox from 1985 to 1991 was fragile, to say the least.

8. THE ALARM: From 2001 to 2005, Harley thinking to do well, had installed an electronic alarm system on all the production. To do well, this alarm was systematically activated as soon as the contact was cut for about thirty seconds. It was therefore not easy to refuel the car or to talk with a friend. Moreover, these alarms were sensitive to the waves of the radio and telephone transmitters. You had to carry the little reminder with the codes to deactivate the alarm and be able to leave. Harley changed the system in 2006. It is more rational.

9. THE SECONDARY BELT: Harley Davidson recommends changing it every 60 000KM, but it is designed to support 100 000km. Only its rupture does not prevent and can be dangerous. In any case, you won’t be able to start again, you’ll have to call the service department. So change this belt every 60,000 km, or sooner if you see it fraying or with holes. 

10. DISTRIBUTION CHAIN: The first H-D motorized by the Twin Cam were victims of a chronic weakness of the distribution chain or drive of the two camshafts (Replacement made during the warranty by the Harley-Davidson network) since the problem completely solved.

How many CC is a 103 cu Harley Motor? 

According to the Harley Davidson Company, 103 cu Harley motor is a 1690 cc bike. They released 1690 cc 103 cu Harley motorcycle for 2010 Electra Glide Ultra Limited models.  

Harley Davidson Engine 

The H-D is powered by the traditional V2 engine with a displacement of 1,690 cubic centimeters, 103 cubic inches in American. It is semi-fluid-cooled, meaning that only the more important parts, such as the cylinder covers, are water-cooled. With a stroke length of 111.1 mm and a piston diameter of 98.4 mm, we can assure you that almost every working pressure is known.

The engine is fed by electronic fuel injection. There is only one throttle body. From the flap, the air duct splits into a twin-curved intake manifold. Fuel injection nozzles are mounted at the top of the intake manifold. There are four valves. The exhaust gases exit the world through a 2-1-2 type pipework. On the way, the gases are cleaned by a catalytic converter.

The engine and the six-speed gearbox are of different castings. They are connected by a bolted joint. The primary drive from the engine to the gearbox is utilizing a chain tightened by an automatic clamp. At the end of the crankshaft is a vibration damper to cushion the engine’s shocks to the transmission. However, the shocks are felt despite the vibration damper’s action. 

Don’t expect to get direct answers from Harley dealers on this subject. If you want to own and ride a Harley Davidson regardless of its dual-cam engine problems, then you need to help your bike yourself. The good thing is that you can take some steps to fix the problems and avoid catastrophic engine problems in the future.

Is it really dangerous if my Harley Davidson Twin Cam engine is broken?

If this kind of problem is not solved and not observed, then there will be a risk that the complete Twin Cam engine will be damaged; cams, pistons, and even the engine case. This is a very serious engine problem that requires a lot of attention to correct.

The scary part here is that it can fail at 15,000 miles and even the new hydraulic system can fail at 40,000 miles or less. The plastic shoes need to be replaced every 40,000 miles because of their poor durability.

Another scary aspect here is that even new engines still have the likelihood of having the same problem as older engines. It’s important to check engines before buying a motorcycle. If it has a cam chain engine, there is a small chance that it will come with the problems we discussed earlier.

Harley 103 Cam Chain Tensioner 

Usually, the chain tensioning system in Harley 103 cam uses plastic riding shoes on the chains of the camshaft which most of the time wears out and creates issues for the rider. This issue is an outcome of the design failure by Harley Davidson.

They should have done a better job with this or at least provide a permanent solution to this in their later fixing initiative. But they were failed to do so. Therefore, owners are affected by it throughout the years. Here we are providing two solutions for this to have a better chain tensioner for your Harley 103 camshaft: 

Firstly, try to get rid of the old chain system and install a new one to replace the chain system entirely. You can also switch to gear-driven cams to get better results. It will cost you $750 without installation charge but will provide you a permanent solution regarding this problem. 

Secondly, you can upgrade or fix your old chain tensioner for a lesser fee of $400 without an installation charge. Harley Davidson won’t provide you any fixing kit with the bike because they never thought of this issue in the first place. Therefore, fixing or upgrading on your own can be an ideal solution to this problem. 

Harley 103 vs. 107 Reliability

When we will compare the reliability between Harley 103 and 107, it will always be Harley 107 which will prevail every time. There are only four valves in Harley 103 whereas Harley 107 has eight (twice in number). 

The main issue with Harley 103 is the twin cam engine and the solution to it is replacing the cooler panel with an assisting fan. Harley 107 has already a better cooling panel and therefore it doesn’t have any twin-cam engine issue. 

In terms of power generation, Harley 107 is far ahead of Harley 103 and therefore you can put your trust in the 107 engine wherever you go. 

Harley 103 and 107 have almost the same combination of rubber-mounting and counterbalancing. There are no specific differences between these two in terms of this. 

Harley Davidson 103 Engine Upgrades

Harley Davidson bike is all about making your bike into an extended version of yourself. But owning a Harley Davidson has its perks and cons. First, you fall in love with the bike and buy it for yourself. Later, you put all your efforts to make it better and faster in different ways.

This is what engine upgrades are all about. Engine upgrades will enhance the look of your Harley Davidson bike and bring a change to the sound and performance as well. There are different stages of engine upgrade for Harley 103 and here they are as follows: 

Harley Davidson Stage 1 Kit for 103 CC

Sometimes people are looking for the basic and simple upgrade for their 103 engine which will enhance the performance, outlook, and sound of their Harley Davidson 103 cc. In case of similar requirements, Stage 1 upgrade can provide all three and deliver you the desired version of your Harley Davidson. 

The key with this upgrade is an oiled cotton filter which will maximize the airflow for the engine. It will even filter contaminants at the same time. This stage 1 kit works through increasing airflow.

When more amount of air comes in and out of your bike engine, then it increases the availability of the potential power automatically. Stage 1 kit will also provide you choices for increasing the performance of your bike as well as customizing the look of your motorcycle. 

Harley Davidson Stage 2 Kit for 103 CC

The stage 2 upgrade involves camshaft changing. You can look for a stage 2 torque kit online which will provide you an incredible and drastic improvement when you are accelerating by targeting a lower RPM performance.

A stage 2 power kit can increase the rev limit to 6400 RPM which will be suitable for a mid-range horsepower engine.

If you can buy and install a good kit in the stage 2 upgrade, you can get 30% of more horsepower and 10% of more torque at the same time.

But it will demand professional installation and tuning to get that result. One more thing to add, if your dealer installs the stage 2 kit, then your warranty will stay in place otherwise it won’t be available later. 

Harley Davidson Stage 3 Kit for 103 CC

Stage 3 kit will ensure the upgrades of big cylinders and pistons. A new and bigger cylinder will provide an increased diameter for higher compression to the engine and forged aluminum pistons will make sure of more power and balance to the engine.

More airflows will be available for enhanced combustion and a better compression ratio.

In addition, there will be high-capacity lifters, clutch components, a cam bearing, and gaskets to make sure everything works together smoothly. After stage 3 upgrade, a 103 cc Harley engine will get 24% off more torques and an incredible amount of 34% of horsepower. 


How reliable is the Harley 103 Engine? 

You all are aware of the reliability of the 96 Harley engine. Harley 103 engine has the same commitment of reliable service. There are no significant differences that can make one less reliable. So, if you have already used Harley Engine, then you will also admit the reliability of Harley engines. 

How many miles will a Harley 103 last? 

A Harley 103 will certainly last for over 150,000 miles. But if you can keep it serviced according to the mechanics and ride on after that, then you will surpass the limit we provide first. But to keep hitting 150,000 miles landmark, you will also require to replace the comp once or twice. Otherwise, it may break down earlier. 

How many horsepowers is the Harley 103 Engine? 

Harley 103 engine is a 103 horsepower engine with 110 lbs.-feet of torque in it. 


Harley Davidson is a complete bike but still, it has its issues and problems which may cost you some money and trouble. But in terms of longevity and reliability, no bike can match the level of Harley Davidson. In fact, with 3 stages of upgrades, your motorcycle can get a new life and rhythm regularly. Proper maintenance will enhance its performance and look all the time. Finally, if you are a Harley Davidson fan, you should also learn about the problems and solutions of their bikes before buying one. 

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