I often get asked if you can run your Jet Ski out of water or can a Jet Ski be run on a Trailer? This fear comes from other forms of boats that require them to be in water before starting. Watercraft use a totally different system for cooling the engine.
Running a Sea-Doo Out of Water
A Seadoo is very different than all the other brands of watercraft on the market when it comes to cooling the engine. A Seadoo doesn’t use lake or ocean water to cool it down but instead uses antifreeze just like your car does.
But this does not mean you can run a Seadoo out of water or on a trailer for very long. This is because the exhaust system uses lake water to keep it cool and when it’s not in water it starts to overheat.
Every watercraft is different but I wouldn’t run it out of water for no more than 15 seconds – its best to use your own judgment.
There is a flush adapter in the rear of a Sea-Doo that allows you to run the watercraft out of the water because it’s getting its water from the garden hose. Consult your owners manual for any procedures for running the watercraft out of the water. If you don’t do it right you run the risk of hydro-locking your engine which is very bad. In most cases, you need the engine on first before you turn on the water hose. Then you turn the water hose off before turning the jet ski engine off. If you can’t find your owners manual then click here to download it.
Yamaha, Kawasaki, and others
The other brands don’t use closed loop cooling and they do take in water to cool the engine. They still can be run out of the water for a few seconds also but the entire engine and exhaust is not being cooled.
The way these jet skis get water is not like a boat where it has a spinning fan that needs to be in the water. These Jet Skis use the impeller as a pump and there is a little hole in the pump for it to flow water through to cool the engine.
Please consult your owners manual for the correct procedure on running your jet ski on the hose. If you do it wrong you can hydro-lock your engine. In most cases, you need the engine on first before you turn on the water hose. Then you turn the water hose off before turning the jet ski engine off. Here is a video that better describes how to do it on a Yamaha.
Jet Ski Is Loud Out of Water
If you do fire up your watercraft out of the water it can be loud and even sound like balls rattling in the back. This is normal. The rattle sound you hear is from the pump and since it’s not in the water it’s not floating so it bounces around.
The other part of the sound is the exhaust because it’s not in the water and the water is used to muffle the sound.