Motorbike Stalls in a Flooded Street: Don’t Try to Restart It Right Away

When a motorbike stalls in a flooded street, the first instinct is to restart it. Heavy rain, a flooded street, and halfway through the water the engine coughs and dies. Almost everyone’s reflex is to keep hitting the starter or kick it over until it catches. This is exactly when engines get damaged.

Why you should not restart it

Bikes usually stall when water gets into the air intake or the exhaust. If water has reached the combustion chamber and you crank the engine, the piston tries to compress water. Water does not compress like an air-fuel mix, so it can bend the connecting rod and ruin the engine. That repair costs far more than calling a mechanic.

Once the engine has died

• Turn the key off. Do not crank or kick-start.
• Get off and push the bike to higher ground out of the water. On a manual bike, shift to neutral.
• If there is a repair shop nearby, push it straight there. The mechanic will remove the spark plug, drain water from the cylinder and air filter, and check the oil before starting it.

A basic self-check

If there is no shop nearby and you know a bit about bikes:

• Open the air filter box. A soaked filter means water got into the intake.
• Pull the oil dipstick. Cloudy oil that looks like milky coffee has water in it and needs changing before you ride on.
• On scooters, deep water easily gets into the transmission case and the drive belt slips. If the engine revs but the bike does not move, it needs attention.

If you are not sure, do not do it yourself. Call for roadside help or push it to a shop. If your motorbike stalls in water, resist the urge to restart it.

Before riding into water

• Watch the vehicles ahead. If the water is above half the wheel or up to the exhaust, find another way.
• Ride slowly with steady throttle. Do not stop halfway or snap the throttle shut. Going fast creates a wave that splashes into the air intake.
• Keep away from cars and trucks; their wake washes over motorbikes.

After the flooded stretch

Wet brakes grip poorly. Squeeze the brakes lightly a few times while riding slowly to dry the pads. At home, wash the mud off the underside, chain and brakes. If the bike stalled in water, change the oil soon even if it restarted.

This rainy season, if your motorbike stalls in flood water, remember these steps. Learn more about hydrolock, or read our weekly motorbike tire check.