ATVs offer unique off-road capabilities and can handle some of the roughest and most unforgiven terrains you can imagine. However, there might come a time where you need to cross a body of deep water out of necessity (if it’s on your path) or simply because the daredevil in you thinks it could be fun.
But before you plunge your ATV into the water, you should know how it’s going to fare when submerged.
A stock ATV is designed to cross small rivers and streams that are not deeper than up to the bottom of the footrests. You should never drive an ATV in deep or fast-flowing water as this may cause engine damage and involve a risk of being swept away with the current.
How Deep in Water Can a Stock ATV Go?
As a general rule, you should never take your stock ATV in water that is deep enough to go past the footrests or footboards of your vehicle. When applying this guideline, you can be reasonably confident that the water will not damage your machine.
If you submerge the ATV beyond this level, you face a list of potentially harmful issues, as outlined further down in this post.
In reality, most ATVs can go somewhat deeper than the footrests safely, as long as you drive at a slow pace and there are no strong currents. How deep your specific ATV can go depends on the location of the air intake and the location of the vent ports for the belt housing. It’s a good idea to identify where these ports are located so that you know your vehicle’s limit.
If you decide to go in water deeper than the bottom of the footrests, make sure to go as slow and steady as possible with no sudden movements as this can cause water to splash higher up on the vehicle than necessary.
Also, check the water depth and current before you attempt the crossing to avoid unexpected surprises. Look out for hidden rocks or other obstacles. See if you can find a crossing that has gradual inclines on both sides for a smooth transfer from land to water and back up on dry land.
This Is What Happens if You Ride an ATV in Deep Water
When a stock ATV goes in deep water, quite a few things may go wrong. In the best case, you only get stuck and need recovery. In the worst case, the water may cause major engine damage or damaged electrical components. You also face the risk of flipping or getting swept away from strong currents.
Water Entering the Engine Can Cause Major Engine Damage
Riding in deep water may cause the engine of your ATV to flood. This happens when water gets sucked in through the air intake and enters the combustion chamber and may cause the engine to hydro lock or water lock. This phenomenon may cause severe dame to the engine.
Typically, the piston moves up and down inside the cylinder and compresses the air trapped between the cylinder head and the piston. The air is then released through the exhaust ports.
However, water does not compress as air does. If water gets trapped where there’s only supposed to be air mixed with gas, the water has nowhere to go as the piston moves up.
If you’re lucky, the engine only stops without any further damage. If you’re not so fortunate, hydro locking can cause significant engine damage to an extent where you may need a major engine rebuild or replace the engine altogether.
Typical damage from hydro locking bent connecting rod, cracked crankshaft, fractures in the cylinder walls, blown oil seals in the cylinder head, and blown valves.
Engine damage is more likely to occur if the engine stops from hydro-locking at a higher engine speed (RPM) than from driving at a slow pace at a low RPM. If hydro locking occurs when the engine is running at full tilt, a connecting rod can snap right off and blow straight through the engine block.
Attempting to start an engine that has stopped from being submerged can also cause engine damage. That is why you mustn’t try to start the engine that before it’s thoroughly inspected.
Please refer to your user manual for vehicle-specific guidelines on what to do before you start an ATV immersed in water. If you don’t have your user manual at hand, you can head over to our guide with general guidelines on repairing a submerged ATV.
The Drive Belt May Get Wet, Causing Loss of Traction
This issue only affects ATVs with a drive belt; most recreational and utility ATVs, and some youth ATVs on the market, except Hondas.
The drive clutch, connected to the engine, uses friction to transfer engine power via the drive belt out to the driven clutch connected to the wheels via drive shafts.
The clutch and belt assembly is located inside a protective casing known as the clutch or belt housing. The friction between the belt and clutches that occur from regular operation generates a lot of heat the needs to be removed to prevent belt overheating and consequently belt slippage.
The belt housing has two ports to keep the system cool, one that sucks cool air in and another that blows warm air out from the case.
If the intake port ends up below water, it will suck water instead of air into the case, effectively soaking the belt and clutches in water.
When the belt and clutches get wet, they lose almost all friction causing the clutches only to spin. The wheels will not turn when this happens, regardless of what gear you use or how much throttle you apply.
The only way to get the ATV moving again is to remove it from the water and drain the casing by removing the drain plug at the bottom.
Recovering a stuck riding buddy is just one way to use your winch; here are 28 other cool ideas for ATV winch uses.
Buoyancy May Cause the ATV to Tip
Stock ATVs don’t float, but buoyancy will cause the ATV to get top-heavy and more likely tip when you drive in deep water. ATVs with bigger tires are more prone to tipping than bikes with stock tires, as bigger tires with more air equal more buoyancy.
Strong Currents May Cause the ATV to Get Swept Sideways
You’s be surprised how little water it takes to sweep away an ATV, as long as the current is strong enough. Even waters depts that don’t reach the footboards can cause a potential hazard after heavy rainfall when water speeds are higher.
It’s not a fun experience when you lose control of the ATV, being swept uncontrollably out into potentially deeper waters.
Wet Brakes Have Reduced Stopping Ability
Keep in mind that wet brake pads and brake discs provide reduced stopping power. After submerging them in water, you should dry them by driving slowly and applying the brakes lightly several times until you feel regular braking action is restored.
Electronic Components and Connectors May Short Circuit or Corrode
As you may know, electronics and water does not go well together. While most electric components such as the ECU and other control units are designed to be waterproof, there is no need to push your luck. Just a tiny amount of water can cause these expensive units to short circuit beyond repair.
Electrical connectors do not short circuit from being submerged in water, but corrosion may cause a bad connection in time.
How to Modify an ATV to Go in Water
A stock ATV can be modified to better cope with being submerged in deep water. Here is a list of the most common mods to achieve deep water or mudding capabilities.
Install a Snorkel Kit
A snorkel kit shifts the air intake or exhaust ports to a higher position on the ATV to prevent water from entering the engine and belt housing. The three ports that need to be snorkeled are:
- The airbox intake (engine air intake).
- The clutch housing vent intake port.
- The clutch housing vent exhaust port.
Some snorkel kits even include an exhaust snorkel to prevent water from entering the engine through the exhaust system.
Other parts you may consider snorkeling are the crankcase breather tube, differential vents, or carburetor vent tubes.
Relocate the Radiator
Submerging the radiator will not cause damage to your ATV. But the stock location of a radiator is prone to get packed with mud and debris if you plan on going mudding regularly.
Relocating the radiator up to the top of your front cargo rack ensures easy access for cleaning and may avoid overheating issues and potential engine damage down the line.
Grease All Electrical Connectors
A cheap but efficient way of protecting electrical connectors from water and corrosion is packing them with di-electric grease before submerging them in water.
Disconnect all connectors and pack them with grease before reinstalling them. Only use di-electric grease as it’s non-conductive and won’t cause a short.
Related: 26 Essential ATV mudding mods.
What to Do if You Have Already Ridden Your ATV in Deep Water?
If you’ve already ridden your stock ATV in deep mud or water, there are consequences you need to attend to, but all is not lost. I’ve structured the somewhat tedious process of repairing a submerged ATV in my guide 16 Steps to Repair an ATV Submerged in Mud or Water
What Is the Purpose of a Snorkel on an ATV?
The purpose of installing a snorkel to an ATV is to relocate the engine air intake, clutch housing vent intake, and clutch housing exhaust port to a higher position on the ATV. This allows the ATV to go in deep water without causing damage to the engine or belt slipping from a wet drive belt.