The 2004 Harley Davidson Fatboy holds a special place in the hearts of many motorcycle enthusiasts.
With its robust build and timeless design, it’s a model that has won acclaim worldwide. However, like any vehicle, it is not without its share of issues.
In this article, we will dive into the common problems associated with the 2004 Harley Davidson Fatboy, providing insights and possible solutions.
2004 Harley Davidson Fatboy Problems
Some owners have reported issues with the bike’s electrical system, particularly the voltage regulator, leading to frequent battery drain.
Furthermore, the model’s cam chain tensioner has been a cause for concern due to its potential to wear out and cause serious engine damage.
Other common issues include oil leaks, especially from the rocker boxes, and the presence of excessive vibration at certain speeds.
1. Backfires Issue
One of the common issues is backfiring. Backfiring usually occurs during a quick deceleration, as the engine runs rich.
This happens when unburned fuel ignites inside the exhaust system, resulting in a loud bang.
To mitigate this problem, inspect the carburettor to ensure it is delivering the correct fuel-to-air ratio to the engine.
An overly rich fuel mixture can cause backfiring. Adjust the mixture screw accordingly, or consider getting a high-flow air filter to improve air intake.
Next, check for exhaust leaks. Air leaking into the exhaust system can cause the fuel mixture to ignite prematurely. If you find any leaks, repair them.
An ignition system that is out of timing can also bring about backfires. Check the ignition timing and adjust if necessary.
However, the timing adjustment on the 2004 Fatboy models requires a special tool and a specific procedure, so it is advisable to have this done by a Harley technician.
2. Fuel Problem
One common issue owners have faced related to the fuel system, particularly related to the carburettor.
This problem may result in various ways, such as rough idle, difficulty in starting the bike, and engine misfiring.
Which could be due to clogged jets or an improperly adjusted float level inside the carburettor.
To resolve this, follow the steps below:
- Remove the carburettor from the bike, ensuring you take note of all connections for proper reassembly.
- Inspect the carburettor visually for any signs of wear, damage, or dirt accumulation.
- Use a carburettor cleaning solution to clean the carburettor. Make sure all jets, especially the main and pilot jets, are clear of any debris.
- Refer to the service manual for the correct float level. An incorrect float level can lead to poor fuel delivery, affecting the bike’s performance.
- Reassemble the carburettor and reinstall it on the bike. Start the bike and let it idle for a few minutes to ensure the issue is resolved.
Remember, dealing with fuel systems can be dangerous due to the risk of fire.
Always take necessary precautions, such as working in a well-ventilated area, free from any potential sparks or flames, and having a fire extinguisher nearby.
3. Clutch Issue
One of the notable problems encountered with the 2004 Fatboy is related to the clutch system.
Owners have reported clutch dragging issues, where the clutch fails to fully disengage even when the lever is fully pulled in.
This leads to difficulty in shifting gears, a feeling of the bike “creeping” forward while the clutch is engaged, or even stalling when coming to a stop.
The root cause of this issue can often be traced back to a worn-out clutch cable or improper clutch adjustment.
If the clutch cable experiences wear and tear or stretches over time, it can prevent the clutch from fully disengaging.
On the other hand, if the clutch is not properly adjusted, it can also result in clutch drag.
Here’s a basic guide on how to address this issue:
- Check for any visible signs of wear or damage. If the cable is frayed or stretched, it needs to be replaced.
- Follow the manufacturer’s specifications for clutch adjustment. This usually involves adjusting the clutch cable’s free play at the lever and the clutch release mechanism’s adjustment located on the clutch cover.
- If the cable is worn out or damaged, replace it. Make sure you choose a high-quality replacement to ensure longevity.
4. Engine Problem
Users have reported instances of the bike stalling unpredictably. This is often linked to issues with the carburettor, particularly if the bike has been sitting idle for a prolonged period.
To diagnose this, check for any visible signs of damage or wear on the carburettor.
If there are no physical signs, it’s recommended to clean the carburettor thoroughly. This can be done by disassembling it and cleaning each part using a carburettor cleaner solution.
After cleaning, reassemble the carburettor and reinstall it. If the problem persists, consider adjusting the idle speed and mixture.
However, if the issue is still unresolved, it may be necessary to replace the carburettor completely.
5. Suspension Issue
The 2004 Fatboy has been noted for certain suspension issues, particularly concerning the front fork.
Riders have reported an uncomfortable riding experience due to a harsh, bouncy ride, indicating a possible issue with the front fork’s damping functions.
The front fork’s purpose is to absorb impact from the road and maintain tire contact. If it’s not properly absorbing the shocks, the ride quality diminishes.
This could be due to a variety of reasons, such as worn-out fork oil, damaged seals, or degraded springs.
To address this issue, begin by checking the fork oil. If it appears dirty or if the oil level is low, it needs replacing.
Remove the fork from the bike, drain the old oil, and replace it with new, high-quality fork oil. Make sure to use the correct oil weight recommended by Harley Davidson.
Next, inspect the fork seals for any sign of wear and tear or leakage. If there’s any damage, replace the seals immediately.
Use a seal driver to remove the old seal, and then carefully install the new one to avoid damage.
Finally, test the fork springs for any signs of sagging or damage. If the springs are damaged, they won’t be able to maintain the necessary tension in the fork, hence a bouncy ride. In this case, you’ll need to replace the springs.
6. Electrical Issues
A common issue that has been reported with the 2004 Fatboy relates to its electrical system.
This problem results in difficulties in starting the motorcycle, intermittent power loss while riding, and malfunctioning lights.
The starting problem could be due to a weak or dead battery or corrosion terminals.
For checking, use a multimeter to test the battery voltage. The voltage should be around 12.6 volts. If it’s significantly lower, the battery might need to be replaced.
Some owners also face a blown fuse, a burnt-out bulb, or a faulty switch. Check the fuse box first, and replace any blown fuses.
If the lights are still not working, inspect the bulbs for any signs of wear and replace them if necessary. If the problem persists, it might be the light switch that’s faulty.
Before doing any of these, make sure to disconnect the motorcycle from its power source to ensure your safety.
Harley Davidson Fatboy Specs
| Specification Category | Specification Details |
| Performance | |
| Max Power | 86 bhp |
| Max Torque | 107 ft-lb |
| Top Speed | 110 mph |
| 1/4 Mile Acceleration | – |
| Engine | |
| Engine Size | 1746cc |
| Engine Type | 45º pushrod V-twin |
| Fuel and Consumption | |
| Fuel Capacity | 18.9 litres |
| Average Fuel Consumption | 18.9 mpg |
| Tank Range | – |
| Brakes | |
| Front Brake | 1 x 292mm discs, four-piston calipers. ABS |
| Rear Brake | 292mm two piston caliper. ABS |
| Suspension | |
| Front Suspension | Showa telescopic forks, no adjust |
| Rear Suspension | Monoshock, adjustable spring preload |
| Tyres | |
| Front Tyre Size | 160/60 x 18 |
| Rear Tyre Size | 240/40 x 18 |
| Dimensions and Weight | |
| Seat Height | 675mm |
| Bike Weight | 304kg |
| Frame | |
| Frame Type | Tubular steel double cradle |
| Costs & Insurance | |
| Annual Road Tax | £111 |
| Annual Service Cost | £280 |
| New Price | £17,545 |
| Used Price | £14,400 – £17,500 |
| Insurance Group | 17 of 17 |
| Warranty and Service | |
| Warranty Term | Two years |
Harley Davidson Fatboy User Reviews
By BOSCE
“This motorcycle is the essence of Harley-Davidson. Low, brutish and, well, beautiful. Powerful engine. Good brakes. Surprisingly nimble, low center of gravity, comfortable. Frankly, it’s the best Harley I’ve ever owned – and I have three others, including a 2020 CVO, in the garage. I’m absolutely stunned by this bike – and highly recommend it unless you’re into epic journeys which require a windshield. A windscreen simply kills the bad boy vibe. The new wheels look good and eliminate the side-wind issue on the older models (yes it’s real. Been there, done that).”
By My first Harley
“Fantastic riding experience, looks and sounds of the business. You do need to ditch the standard pipes to get the Harley sound. I added a Vance and Hines Fuelpak to flash the ECU to get the sound and feel that I wanted. It made a huge difference to the standard bike. Handles really well for the style of bike and is very quick off the mark. Its surprisingly stable and vibration free once underway. I would suggest its not for an inexperienced rider as the wide tyres make it feel unwilling to turn.”
By Mr. Never buyaharley
“its slow, the brakes are terrible its so bad at going round bends even the pillon pegs grind out at the first sign of a bend frightens the life out of the wife to think her feet are going to touch the tarmac buy anything but one of these” Source: motorcyclenews.com
Talha Younas, the brains behind the influential motorcycle-focused website, TwoWheller.com, is a dedicated and passionate advocate for biking culture. Born and raised in a family of motorcycle enthusiasts, his love for two-wheeled transportation was ignited at an early age. His commitment to providing in-depth reviews and helpful tips for riders has established him as a respected figure in the motorcycle community.
