Motorcycle Tech Tips

Motorcycle Maintenance - How to Change Oil (Harley-Davidson V-Twin)

Changing motor oil in a motorcycle is an essential maintenance item to keep an engine running smoothly and with longevity. An air-cooled V-Twin with an external oil sump is a very common engine on most Harley-Davidson models. Unlike most models with external oil tanks, some touring models have oil sumps built right into the engine block and can follow a similar procedure to change the oil.

Oil is viscous and that viscosity will break down over time. This breakdown in viscosity means that the lubrication is no longer doing its job to limit the friction between engine parts. When this happens, engine oil becomes thin and carries dirt particles. This is why engine oil must be changed from time to time.

Mineral or synthetic oil?

Engine oil comes in two forms: it can be mineral or synthetic. Synthetic oil tends to be more expensive, but does last longer. Refer to the manufacturer’s engine manual to determine what type of oil works best for your vehicle.

Oil weights

Most air-cooled engines use heavier weight oil. A common oil weight for Harley-Davidson V-twins is 20-50 weight. Straight weight oils do not shear to the thinner weight in colder temperatures and therefore may cause issues when operating a motorcycle in colder temperatures. Thicker oil cannot pass through oil passages because it is too thick.

changing oil in motorcycle

Changing your oil: step-by-step

Here are a few steps to change the oil in a Harley V-Twin motorcycle:

  1. Warm engine up to operating temperatures (go for a short ride).
  2. Locate engine oil drain (some oil tanks have hoses hanging with a removal plug; other tanks just have a plug at the bottom).
  3. Remove the oil drain plug and catch oil into a pan.
  4. Replace the oil drain plug.
  5. Remove the oil filter (some motorcycles have external remote filters; some have filters on the engine block) and catch remaining oil into a pan. If it is tight, a band wrench can remove it.
  6. Put a small amount of clean oil into a new oil filter and gently lubricate the seal with clean oil. Hand-tighten the oil filter onto the motorcycle. It does not have to be extremely tight.
  7. Dirty oil can still be in the engine case and the lower oil lines because of the external oil sump system. The tricky part is getting that oil out. Locate the oil return line from the engine case to the oil tank. Remove the side from the oil tank, but leave the engine side on. Fill the oil tank with clean oil. Either with help from a friend or done very carefully, start the engine with the oil return line going into an oil pan to catch dirty oil. Run the engine and observe the dirty oil coming from the return line. Once clean oil is coming from the return line, shut down the motorcycle and reconnect the line to the oil tank. At this point, all the dirty oil has been flushed from the engine.
  8. Top off the engine oil and check the level. Make sure the bike is not leaning on its kickstand when checking the level; this will give an inaccurate reading.
  9. Go for a short ride and check the oil level once more.

It’s that easy! Use this teach tip to change the engine oil on a Harley V-Twin motorcycle yourself and save a lot of money at the shop. Remember to always purchase good quality oil and filters so your motorcycle will operate smoothly for years to come!

This information is provided for general informational purposes only and is not a substitute or intended as professional advice. Please be sure to refer to your owner’s manual or consult a mechanic for information specific to your motorcycle.

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