How to: Flush oil and other fluids from a flooded motorcycle

DIY guide to oil changing flooded motorcycles

The last few weeks was very challenging for many of our fellowmen as typhoons ravaged Luzon. This then resulted in massive flooding in many low-lying areas. Houses were submerged, along with some of the tools of their livelihood and vehicles like cars and motorcycles.

As the floodwaters subside, many are beginning to pick up the pieces and move on with their lives.

If your motorcycle was flooded, we list down the things to check and steps to do in this story. Of course, it entails contacting your service center or casa and preparing yourself for the inevitably large bill.

For the not-so-complicated motorcycles such as underbones, older scooters, and even old big bikes, you can actually revive them yourself and save a few thousand pesos in labor costs with DIY-style maintenance work.

In this story, we will be focusing on proper oil flushing (and other liquids) that you can do by yourself and get your motorcycle back in running order.

What is oil flushing?

In a broad sense, oil flushing is drains all the old oil that is still left inside the engine, then replacing it with new and fresh oil. Though there are many oil flushing additives which are readily available and promise to clean accumulated deposits, sludge and other gunk from your engine, mechanics usually recommend flushing the old oil with fresh oil, especially for those with flooded units.

Flood water is not just water but also suspended dust and dirt particles. It's these solid particles in the flood water that is the most dangerous. If flood water is not completely removed from the engine, it may accelerate the wear and tear of the motorcycle engine's internals or worse, damage the engine. This can cause the owner thousands in repair costs.

Since water is heavier than oil, you may need to perform several cycles of oil flushing on submerged motorcycles to make sure that the engine’s internals are entirely water free.

Tools

To perform this DIY oil flushing, you'll need tools like a socket wrench (preferably a ratchet type) or a closed wrench that matches the size of the drain plug, a philips screwdriver, some rags to wipe spilled oil, and a small basin to catch the draining fluids.

For safety, it is advisable to use latex gloves. Some oils and lubricants may cause irritation to the skin. If you have, wear appropriate eye protection.

Finally, buy the appropriate oil for your motorcycle, as well as a new oil filter if your motorcycle has one.

1. Drain

Water won’t simply seep inside the engine if it was not running when it was submerged in flood waters. However, it can still enter in some cases if the water level is high or the engine is not completely sealed because of a loose gasket.

To check if flood water entered your engine, check the oil level window (if your motorcycle has one) or dip stick to see if the oil has water in it.

If there is water, you’ll need to drain it ASAP. Read the owner’s manual to locate your motorcycle’s oil drain plug. If there is none, unscrew the oil drain plug gently until oil starts dripping down. Have the basin ready underneath to catch it.

You need to observe the oil to determine the damage to your engine.

Since water is heavier than oil, it will drip before the oil does. If no water is dripping, congratulations! Your motorcycle doesn’t need an oil flush.

If you see water, your motorcycle definitely needs oil flushing. Remove the oil cap and drain the oil. If your motorcycle has an oil filter, remove the filter element and return the filter cap.

2. Clean air box and exhaust

While waiting for the oil to completely drain, use this time to check the air box for any signs of flood water by looking at its drain plug. The air box’s drain plug is usually made of a transparent hose-like material that is held in place by a thin wire clamp and is generally somewhere near the rear wheel. If you don’t know where to locate it is, check the owner’s manual. Once you find it, remove the plug.

If there is no water or residue around the screw of the cap, chances are water didn’t enter the air box. But just to be sure, you may also want to remove the air box cover. Once removed, look at the air filter element to see if there are signs of water and mud. This will be sandy residue that's the same color as the flood water. Replace if needed.

If removing the plug leads to water dripping out, the air box needs some cleaning and the air filter element needs to be replaced. Read the owner’s manual on how to replace your motorcycle-specific air filter element.

To check if there is water inside the exhaust pipe, ask two buddies to help you tilt the motorcycle. You need to lift the front wheel of the motorcycle up, like doing a wheelie.

Pro tip: While lifting the front wheel up, make sure to press on the rear brake (scooter) or put the motorcycle on first gear so that the motorcycle won’t roll backwards.

This procedure should drain any floodwater trapped inside your motorcycle’s exhaust system.

Depending on the severity of the situation, a drowned motorcycle may require up to 3 cycles of oil change to completely rid the engine of floodwater.

3. Fill and start

By this time, you're probably already completely drained the oil for the first time. Return the oil drain plug and make sure not to over tighten it. As a general rule, tighten the drain plug using only the force from your wrist. Better yet, use an appropriate torque wrench and follow the correct torque requirement.

Fill in the fresh oil by pouring it into the opening under motorcycle’s oil cap. The amount of oil will depend on the size or type of motorcycle (underbones and scooters usually require only 1 liter of oil). Please read the owner’s manual for the precise amount.

After replacing the oil, return the oil cap and start the motorcycle. Let the engine run on idle for about two to three minutes. Drain the oil again. Repeat this procedure for another cycle or until the oil no longer has the color of coffee with cream.

If you ride is a scooter, consider replacing the gear oil with 3 cycles of oil or until there is no more water in it. Again, if the oil no longer resembles coffee with creamer, it is good to go.

4. Last fill

If your motorcycle has an oil filter, put the new one back in before going on to the third cycle. The third cycle of fresh oil will serve as the new oil your motorcycle will be running normally.

You may also want to clean the scooter’s drive belt and clutch. Lubricate certain points as indicated on your scooter’s manual.

Final tip: Make sure to properly dispose of used oil by bringing it to facilities that handle these types of materials. Do not throw it down the drain. Generally, most gas stations have an oil disposal facility which collects use oil and then sends it to a recycling plant.

These steps just cover oil flushing. For flooded motorcycles, you'll want to inspect the chain or drivebelt as well. Of course, also do a complete pre-ride inspection before riding out for the first time after being flooded.

By following these steps, you should be able to clear your engine of potential foreign particles brought in by the flood water. Once again, we only recommend this for older motorcycles that are out of warranty. It's not a full proof solution, but should get you back on the road at the very least.