Dry Sump Oil Changes, and Why the Oil Is Not in the Engine

On a dry sump motorcycle the working oil supply does not live in the bottom of the engine. It lives in a separate tank. A feed pump sends it to the engine and a scavenge pump pulls it back out of the crankcase and returns it to the tank. The consequence for an oil change is that there can be more than one place to drain, and the order matters. Which points your machine has, and the order to use them in, is a per model fact from its own manual.

Difficulty	Time	DIY cost	Tools	Safety
Moderate, mainly because of the sequence	Around an hour, longer the first time	Oil, a filter and any new sealing washers	Drain pan, correct plug socket, filter tool, funnel, nitrile gloves	Hot oil, hot exhaust, the bike falling, used oil handling

There are no capacities, torque figures or intervals on this page. A number borrowed from a different machine is worse than no number at all.

Before you touch anything

• Hot oil and a hot exhaust. This job is drained warm, and warm oil scalds. A dry sump machine gives you more than one hot cavity to open, and the tank and its hoses hold heat as long as the cases do.

• Fire. Feed and return hoses often run near a header, so oil released at a tank or hose joint can land on a pipe still hot enough to make it smoke. Clean every spill before the engine is started again.

• The bike falling. This job means moving around and under the machine to reach more than one point. Support it so it cannot move, and do not lean on it while a plug is out.

• Used oil on your skin and in your eyes. Wear eye protection and nitrile gloves. A tank drain sits higher than a sump plug, so the oil arrives from further up and with more force, and it can splash back out of the pan. The US Environmental Protection Agency states that used motor oil is insoluble, persistent, and can contain toxic chemicals and heavy metals. EPA does not publish a specific human health outcome from skin contact on its used oil pages, so we do not claim one either. Read the EPA used oil guidance.

• Enclosed spaces. Never run an engine in a closed garage, including the warm up run this job starts with.

What a dry sump actually is

On a wet sump engine, oil collects in a sump at the bottom of the crankcase, a pump draws from a pickup sitting in it, and the oil falls back into the same space. The reservoir and the engine are one enclosure, which is why a wet sump machine normally has a single drain plug at the lowest point of the engine.

On a dry sump engine the reservoir is somewhere else, and there are two pumping jobs rather than one. A feed pump takes oil from a separate tank and pressurises the engine. A scavenge pump takes the oil that has collected in the bottom of the crankcase and pushes it back to the tank. The name describes the intent: the sump is meant to be kept clear of standing oil, because the oil is meant to be in the tank. The reservoir therefore goes where it fits rather than where the crankshaft is, and the oil ends up distributed across several places at once: some in the tank, some in the hoses, some in the crankcase, some in the filter.

The visible clue is usually a separate oil tank with hoses running to the engine, and a filler and level check that is not on the engine cases. Some designs hide the reservoir inside the frame tubes, so a machine can look as though it has no oil tank and still be dry sump.

What we will not tell you is which models are which. That needs the manufacturer's own documentation. We do not publish a model list, because a wrong entry sends somebody under a bike hunting for a drain plug that is not there, or leaves half the old oil in the machine. The lubrication section of your service manual settles it in a minute.

Why the drain points, and the order, matter

On a wet sump machine one plug empties the reservoir. On a dry sump machine, pulling only the tank drain leaves whatever is sitting in the crankcase, the hoses and the filter. So there may be a tank drain, an engine drain, and on some designs a further drain at the low point of a hose or at the filter housing. Some designs have one. The manual tells you which, and we cannot, because it does not generalise.

The order matters for two reasons, and the second is the one people miss. First, oil moves when you open a cavity, sometimes into a place you have already drained. Second: the fill quantity in your manual assumes the manual's drain procedure. A published quantity is not a measure of how much oil the machine holds. It is the amount that produces a correct level after that sequence, leaving that residue behind. Drain in a different order, then fill to the printed figure, and you are pouring a known quantity on top of an unknown one. That is how machines get overfilled by people who followed the number carefully.

The drain, step by step

1. Warm the engine as the manual instructs, then stop it and let it cool to a temperature you can work at. Outside, not in a closed garage.

2. Set the machine in the attitude the manual specifies. The level reading depends on it, so establish it now rather than after filling.

3. Put a large pan under the first point in the manual's order. Oil out of a tank comes faster, and from a greater height, than most people expect.

4. Remove the plug and keep its sealing washer. Note which plug came out of which hole. The plugs are not necessarily the same length, thread or seat, and one fitted into the wrong location is an easy mistake and a hard one to spot later.

5. Look at what comes out, and at the magnet if there is one. A fine grey fur on a magnet is normal. Flakes, glitter, or particles you can feel between finger and thumb are a finding about the engine, not about the oil change.

6. Work through the remaining points in the manual's order, letting each drain properly rather than rushing it.

7. Refit each plug with the correct washer and tighten to the manual's torque. Aluminium cases are not forgiving, and a stripped drain thread turns an oil change into a case repair.

The filter and the hoses, while you are in there

The filter holds oil, so it is part of the drain, and its architecture changes the job. That is a subject of its own, covered in spin on or cartridge, how the filter changes the job.

The hoses are the part unique to this layout. Feed and return lines carry oil outside the engine, so look for hardened or weeping ends, a line resting against a frame tube or a header, and a clamp that has relaxed. A hose failure here does not lose a splash of oil, it loses the supply. If a hose is disturbed, check whether the manual gives a priming instruction.

Refilling, and the level check people get wrong

Two different things move the level and they move it opposite ways. After a total drain the engine, lines and cooler are empty, so the first run pulls oil out of the tank and the level falls. On a machine that has simply been parked, oil migrates from the tank into the crankcase while it stands, so the tank reads low before you start it and rises once the scavenge pump has returned that oil. Never add oil to a stood machine on a cold reading. Run it as the manual specifies first, then read it the manual’s way.

Fill to the manual's quantity, run the engine exactly as it says, then check the level exactly the way it states. Hot or cold, running or stopped, upright or on the side stand, dipstick screwed in or resting on the threads: those conditions are not interchangeable, and every manual picks one and means it. A reading taken before the engine has run is not the measurement the manual means.

Specifications you need to look up for your bike

Value	Why you need it	Where to find it
Number and location of every drain point	Knowing what you are emptying, and what you would otherwise leave full	Factory service manual
The order to drain them in	The fill quantity assumes it	Factory service manual
Oil quantity, and whether it differs with a filter change	Refilling to the correct level	Owner's manual and factory service manual
Oil specification and viscosity grade for your machine	Choosing the oil	Owner's manual
Drain plug torque, and which plugs take a new sealing washer	Not stripping a case, and not leaking	Factory service manual
The level check procedure and the exact machine state for it	It is the only reading that means anything	Owner's manual
Filter part number and its fitting instruction	Fitting and tightening it correctly	Owner's manual and the filter itself
Whether the system needs priming if a hose is disturbed	Avoiding a dry start	Factory service manual
Service interval for your model and how you use it	Knowing when to do this again	Owner's manual

When to stop and take it to a shop

Stop if you find metal in the drained oil beyond a fine magnetic fur, because that is a diagnosis rather than a maintenance item. Stop if a drain plug will not seat or weeps after correct torque, since repeated attempts turn a repairable thread into a case replacement. Stop if you cannot establish the drain sequence, the fill quantity and the level check procedure from real documentation for your machine, because guessing any of the three is the failure mode this page exists to prevent. Stop if an oil pressure warning appears after the change. And stop if the level behaves in a way the manual does not describe, because that is a question about the scavenge side rather than about the fill.

Related checks

• How to change motorcycle oil, and which procedure your bike needs

• Engine, primary and transmission, the three fluid change

• Spin on or cartridge, how the filter changes the job

Frequently asked questions

How do I tell whether my bike is wet sump or dry sump?

Look for a separate oil tank with hoses running to the engine, and a filler and level check that is not on the engine cases. That is the usual sign but it is not conclusive, because some machines use the frame as the reservoir. The lubrication section of the factory service manual is the reliable answer, and it is why we do not publish a model list here.

Which drain plug do I take out first?

The one your manual names first. We will not guess, because the order differs between designs and the fill quantity you use afterwards assumes the manual's sequence. If you have no manual, obtaining one is a step in this job rather than an optional extra.

Why does my oil level read differently hot and cold?

Because the oil is shared between the tank, the engine and the lines, and how it is distributed depends on whether the pumps have been running and how long the machine has stood. The check is only meaningful under the conditions the manual specifies.

Do I have to change the oil in the tank and in the engine separately?

It is one body of oil, so you are not changing two different oils. You are emptying it out of more than one place, because that is where it is sitting. Whether your machine has one drain point or several is in the manual.

What do I do with the used oil?

Keep it out of the ground and out of the drain. EPA states that used oil from one oil change can contaminate one million gallons of fresh water, and instructs you to take care not to spill any, put it in a leak proof container, and check with local automobile maintenance facilities, waste collectors and government waste officials for where to drop it off. Drain and recycle the filter too. EPA says used oil filters can usually go to the same collection centres.

About this guide

Published by MotoGearRater. Universal procedure only, with no model-specific specifications. This guide has not been reviewed by a qualified motorcycle technician, and we say so rather than implying a review that has not happened. Read our editorial standards.