How to Replace a Harley Battery

Harley-Davidson is a well-known American motorcycle manufacturer. Harley owners tend to take care of their bikes as if they were family. Unfortunately, all battery-powered vehicles will need a replacement battery eventually. Like all electrical devices, not all Harley-Davidson motorcycles use the same kind of battery to run. This makes it very important to pay attention when replacing a Harley-Davidson battery. Fortunately, Harley-Davidson makes it simple to replace the battery in a bike when the old one gives out.

Difficulty:

Moderate

Instructions

Things You'll Need

• Protective gloves
• Protective eye wear
• Wrench or Phillips-head screwdriver
• Steel wool
• New battery
• Battery charger

1. • 1

     Protect yourself with gloves and eye protection before beginning. This will protect you from the battery acid you will be dealing with.

   • 2

     Take a look at the battery you want to replace. Make a note of the brand and code number. Use this when searching for a new battery. Not all Harley motorcycles take the same battery. If you're unsure, disconnect the positive (red) and negative (black) terminals from the battery posts using a wrench or Phillips-head (some batteries require different removal methods) and bring the battery with you to the store.

   • 3

     Remove any corrosion on the ends of the wires that connect to the battery. Corrosion causes problems with the flow of electricity. Any corrosion may be sanded down with steel wool.

   • 4

     Purchase the battery that matches your brand and code number. Depending on the type of battery you purchased, you may need to fill the battery yourself with an electrolyte solution. Some batteries are pre-filled. If yours is not, it will come with the chemical solution. To fill it, look for a plastic cap on top of the battery. Remove this cap. Push the bottle of clear or yellowish liquid onto the plastic post on the battery. Put the cap back on.

   • 5

     Charge the battery on a battery charger for 3 to 5 hours (based on what the instructions that came with the battery suggest).

   • 6

     Place the battery back onto it's post. Use a wrench (or screwdriver, whichever is needed) and connect the positive cable (red) to the positive post (+) on the battery. Connect the negative cable (black) to the negative post (-) on the battery.

Tips & Warnings

• Always charge your battery for the recommended duration. If the battery is not charged fully after you purchase it, it will not function properly.

• Connecting the wrong terminal (i.e., positive to negative) can cause serious electrical damage to the motorcycle and/or cause the battery to explode.

• Battery acid contains sulfuric acid which can cause serious damage to the skin and eyes. If battery acid gets on your skin, add a paste of baking soda and water to the acid in order to neutralize the burning.

How to Decode Harley Cylinder Casting Numbers How to Decode Harley Cylinder Casting Numbersthumbnail You will find casting codes on various parts of y

How to Decode Harley Cylinder Casting Numbers

You will find casting codes on various parts of your Harley.

Different numbers are stamped in different locations on your Harley Davidson motorcycle. The Vehicle Identification Number is on the swingarm frame and on the crankcase. Numbers are also stamped on the cylinder. Some might think this is the parts number, but the three-part number stands for the casting number. Casting numbers indicate when the part was cast or manufactured. This lets you know how old the part is. It is possible to have parts with different casting numbers.

Difficulty:

Easy

Instructions

1. • 1

     Look closely at the casting numbers on your Harley cylinder; find a letter and two numbers. Note the two dashes. One comes after the letter, and one after the first number.

   • 2

     Determine where the letter falls in the alphabet. The letter "B" is the second letter of the alphabet. On a Harley that signifies February, the second month of the year. This is the month the Harley was manufactured.

   • 3

     Look at the first number. It indicates the day of the month the motorcycle was made. The second number indicates the year it was manufactured.

How to Change the Transmission Fluid in a Harley

As one of the three fluids that are crucial to a Harley-Davidson motorcycle's operation, the transmission fluid lubricates the assembly of gears that transmits the motor's power to the rear wheel. Much like the oil used by the machine's motor, the oil within the transmission will begin to thin over time. If left unchecked, the thinned fluid begins to lose its ability to lubricate and cool the transmission, creating excessive wear that could cause permanent damage. Replacing the transmission fluid regularly can prevent this from happening. In fact, Harley-Davidson recommends changing the fluid every 2,500 miles.

Difficulty:

Moderate

Instructions

Things You'll Need

• Oil pan
• 5/8" socket
• Socket wrench
• Sealing washer
• Torque wrench
• 1 qt. Harley-Davidson transmission fluid

1. • 1

     Unscrew the filler cap from the right side of the transmission assembly.

   • 2

     Look under the transmission assembly to find the drain plug. Place an oil pan directly below the plug.

   • 3

     Use a 5/8" socket and a socket wrench to unscrew the drain plug bolt. Drain the transmission fluid into the oil pan.

   • 4

     Pull the sealing washer off of the drain plug and replace it with a new sealing washer. Screw the drain plug into the transmission assembly by hand. Use a toque wrench to tighten drain plug to 21 ft-lbs.

   • 5

     Use a funnel to pour up to a quart of Harley-Davidson transmission fluid into the transmission assembly.

   • 6

     Screw the filler cap onto the transmission assembly.

Tips & Warnings

• The drain plug is hidden between the rear shock absorbers on a Softail model. Use a socket extension to remove and reinstall the drain plug.

• Do not overtighten the drain plug. Use a torque wrench to prevent damaging the transmission assembly's threads.

How to Dynojet a Harley

Installing a Dynojet system in your Harley will give you increased horse power and a competitive advantage in close-course racing.

Fitting your Harley-Davidson motorcycle with a Dynojet will help you squeeze out extra horsepower, which is crucial in many races. However, be sure that you will use your motorcycle exclusively for racing, as Dynojet aftermarket kits are not designed for day-to-day driving or street use or on vehicles required to meet emissions standards. Installing a Dynojet will require some mechanical familiarity with your motorcycle. You should know where your carburetor is as well as how to remove it and how to adjust fuel flow.

Difficulty:

Challenging

Instructions

Things You'll Need

• Dynojet kit
• Work gloves
• Safety glasses
• Drill
• Vise clamp
• Small hammer (or) rubber mallet

1. Installation

   • 1

     Select and purchase the Dynojet kit that fits your Harley Davidson model number and options. Read the enclosed manufacturer's instructions carefully. Set aside all parts so that they are within reach.

   • 2

     Secure your Harley-Davidson with the engine off. Put on your work gloves and safety glasses. Remove the carburetor float bowl. Remove any excess gasoline before beginning installation. Remove the main jet holder and replace with the Dynojet emulsion tube. Install the Dynojet main jet by screwing it onto the threads of the emulsion tube. Locate the side lift hole and use the drill bit provided in your Dynojet kit and your drill to enlarge the hole.

   • 3

     Install your Harley's e-clip into the Dynojet needle. Replace your stock slide spring with the Dynojet slide spring. Locate the fuel mixture plug, about 8 inches above the main jet. Turn the fuel mixture screw until it is past 3.5 and then untwist the fuel mixture screw until it is at exactly 3.5.

   • 4

     Replace the carburetor float bowl and reinstall the assembly into your Harley. Haul your motorcycle to a closed track for testing. Check for an increase in acceleration and power but also pay attention to how your Harley handles at regular driving speed. If your Harley struggles to maintain speed, you may need to install a slow jet later to control some of the performance enhancements of your Dynojet.

Tips & Warnings

• Always wear work gloves and eye protection when working on your motorcycle.

• Do not smoke or work near an open flame.

• Remove any gasoline in your carburetor float bowl before attempting to install the Dynojet kit.

• Always wear a helmet when riding and when racing your Harl

How to Change the Oil on a Harley-Davison

Change the oil in your Harley-Davidson motorcycle approximately every 2,500 miles.

Changing the oil in your Harley-Davidson motorcycle is essential to keeping the engine running smoothly. Check the oil in your engine every time you ride your Harley. Most dealers and independent mechanics can charge as much as $100 to change the oil, but it costs less than $20 to do it at home. These instructions are for a Harley-Davidson Sportster, but they correspond to most modern Harley models.

Difficulty:

Moderate

Instructions

Things You'll Need

• Oil filter
• 3 qts. oil (2.8 liters)
• Medium or small flat-head screwdriver
• Oil filter wrench
• Used oil container
• Clean rags

1. • 1

     Remove the oil cap and center the used oil container underneath the filter. Turn the oil filter counterclockwise using the wrench until it's loose enough to turn by hand. Gently remove the filter, angling it up as you pull it off so the oil doesn't spill.

   • 2

     Tilt the filter down and drain the oil into the container, leaving the filter open-side down in the container. Allow all the oil to drain out, wiping the excess off the engine case and the oil-sending unit with a clean rag.

   • 3

     Find the oil drain hose, usually behind the clutch and under the swingarm. Move the used oil container under the hose. Unscrew the clamp on the hose counterclockwise. Pull off the hose, angling it down toward the container to drain the oil inside it. Replace the hose and tighten the clamp clockwise.

   • 4

     Wipe any excess oil off the oil pump. Inspect the new filter for damage. Using one finger, rub a small amount of new oil around the filter's rubber gasket. Pour about four ounces of oil into the filter and hand-tighten it on the oil pump.

   • 5

     Fill the oil tank with oil, just to the bottom of the tank opening, about three quarts (less the earlier four ounces). Replace the oil filler cap.

   • 6

     Loosen the oil drain hose again and let a little bit of the new oil drain out to eliminate any air bubbles in the system. Tighten the hose clamp.

   • 7

     Start your engine. If your oil check light had been on, make sure it's off. Check around the oil filter and drain hose for leaks.

Tips & Warnings

• Choose natural or synthetic oil for your bike, but once you choose, use it consistently.

• If you consistently ride your bike at high RPMs, you should change your oil more frequently to help protect your engine.

How to Replace a Harley Driving Light

Driving lights provide additional light to improve safety.

Harley-Davidson equips some motorcycle models with driving lights, or the bikes may have light bars retrofitted. Driving lights generate almost as much light as the headlight, and project it forward and onto the road. The increased light output can contribute to safety, as the road conditions ahead are more visible to the rider, and the bike is more visible to other traffic. Driving lights can fail due to heavy use or vibration. Replacement of the light poses no difficulty and requires no special tools.

Difficulty:

Moderate

Instructions

Things You'll Need

• Screwdriver Set

1. • 1

     Locate the trim bezel screw at the bottom of the light housing. Loosen and remove the trim bezel screw with a screwdriver. Remove the trim bezel from the light housing.

   • 2

     Slowly remove the driving light from the housing a few inches. Loosen the light wiring terminal screws with a screwdriver. Remove the wiring terminals from the light.

   • 3

     Hold the new driving light near the housing. Install the wiring terminals onto the new driving light and tighten the screws securely.

   • 4

     Gently push the new driving lamp into the housing. Install the trim bezel ring over the housing and driving light. Install and tighten the trim bezel screw securely with a screwdriver.

   • 5

     Loosen the trim bezel screw slightly and rotate the driving light to change the aim point of the driving light, if desired.

How to Change the Oil on a Harley Fatboy

Changing the engine oil and filter is one of the basic maintenance skills every motorcyclist should have under their belt. When done on a regular basis, the lifetime of your Harley-Davidson Fat Boy will be extended by reducing wear caused by contaminated or degraded oil. Although the Fat Boy and most Harley-Davidson motorcycles use three types of oil, replacing the engine oil is a fairly simple task for most motorcyclists and requires only a few tools.

Difficulty:

Moderate

Instructions

Things You'll Need

• Socket wrench
• SAE sockets
• Oil filter wrench
• 3 qts. 20W50 Engine oil
• Oil catch basin or container
• Towels or rags
• Service manual (optional)

1. • 1

     Start the motorcycle and let it warm up for a few minutes. Warm oil will flow better and will help flush out any contaminants that may be present in the oil. Be sure not to let the oil get too hot to prevent burning yourself in the following steps.

   • 2

     Locate the oil drain plug and place your oil catch basin below it. The plug is under the right side of the motor.

   • 3

     Remove the oil drain plug using a socket wrench and inspect the drain plug's O-ring for damage or tears, replacing the O-ring as necessary. Set the drain plug aside.

   • 4

     Remove the oil filter with an oil filter wrench and discard the old filter.

   • 5

     Allow the old oil to drain until the flow has reduced to a minimal trickle. Replace the oil drain plug.

   • 6

     Fill the new oil filter with fresh oil, coating the inner lip of filter lightly with oil to provide a stronger seal before screwing the filter onto the motor. Tighten the filter by hand until it is secure.

   • 7

     Add your engine oil into the oil tank from the oil fill neck (where the dip stick is mounted).

   • 8

     Replace the dip stick and wipe away any spilled oil.

Tips & Warnings

• If possible, consult a service manual for comprehensive details about this process and oil types and amounts.

• Be sure that you have the right type of oil filter wrench for both the old and new filters.

• If you own a 2001 and newer Fat Boy, be sure that the replacement oil filter is capable of filtering down to 10 microns to accommodate the smaller oil passages used by the Twin-Cam 88 motor. Using a standard oil filter will prevent the flow of oil into the motor and will cause serious damage.

• Remove the oil dip-stick to quicken the draining process.

• If you do not feel that you can complete this project, have the work done by a qualified technician.

• Use caution when draining the oil to prevent burns. To prevent the oil from reaching extreme temperatures, only allow the motorcycle to warm up for a few minutes.

• Do not use tools or excessive force when tightening the oil filter to prevent damage.

• Double check that the oil filter cap or dip stick is secured before starting the motor again to prevent spraying oil.

• Do not dispose of used oil in a drain or trash can. Take it to an auto parts store for recycling.