Every year, watersports enthusiasts from all across the nation go out on the water in their personal watercraft (PWC), such as jet skis. This kind of boat is one of the most well-liked ones, and for good reason!
Even while PWC (also known as jet skis, which we’ll discuss later) are popular, few people fully understand how they operate. Jet skis and other personal watercraft may at first look like a cross between a motorbike and a boat, but they don’t belong in either category. They need to be maintained because of the distinctive way they work.
Knowing the fundamentals of how a jet ski operates is crucial whether you want to buy one or work as a technician who fixes them. Read on to find out all there is to know about jet skis, including what they are, how they operate, and their many components.
What Is A Jet Ski?
Let’s start with basic definitions before getting into the intricacies of jet skis and how they operate:
Personal watercraft made by Kawasaki are referred to as “jet skis” specifically under that brand. While the name “jet ski” is unique to Kawasaki, it is frequently used to refer to compact watercraft where the rider sits on top, much like a motorbike. Kawasaki offers both standing and sitting jet skis for sale.
- Similar to that, Yamaha refers to its personal watercraft by the brand name WaveRunner. Yamaha also makes stand-up WaveRunners, but solely for competition on limited courses.
- Yamaha also makes stand-up WaveRunners, but solely for competition on limited courses.
- Personal watercraft, or PWC, is a general word for all small vessels having an impeller rather than a propeller and with the rider standing on top of the hull rather than seated within.
Up to four people can be carried on seated jet skis, which include a bench seat for the rider. Stand-up jet skis are designed for a single rider and include a hinged part that houses the handlebar and other rider controls. This design enables the user to take a kneeling posture before taking a stand once the jet ski is moving.
How Does A Jet Ski Engine Work?
A jet ski, WaveRunner, or other personal watercraft are not just smaller and have different seating arrangements than boats. Another notable distinction is the means of propulsion through the water. PWCs employ an internal impeller to generate force rather than an exterior propeller that is rotating.
Jet Ski Propeller
Traditional boats use an external propeller to provide propulsion force. Even when the engine is operating, the propeller can rotate in either the forward or reverse direction or it can stop (neutral).
Since the propeller hangs very low to the boat hull, boats need a way to raise and lower it. A propeller in shallow water runs the danger of damage without a way to raise it. Personal watercraft instead employ an impeller that is installed within instead of an external propeller.
Steering, Braking, Neutral And Reverse
As was already said, jet skis lack a gearbox that may separate the impeller from the engine. A physical barrier (bucket) sends the outgoing water stream back toward the front of the vessel for reverse or straight down for neutral to accomplish stationary motion or reverse.
The handlebar positioned on the hull is used to swivel the jet nozzle to provide left and right steering. The jet ski cannot steer left or right unless it is powered. Many new riders have the terrifying situation of trying to control the vehicle after releasing the throttle, only to have it continue to float straight ahead!
Jet skis with brakes are not universal. The same bucket that controls reverse may also slow the ship on versions with braking systems. When the rider lets off the power, jet skis slow down even without brakes quite rapidly. So while it might be unsettling to find that a personal watercraft lacks specific “brakes,” riders soon learn that they can slow down simply and securely once they are moving.
Engine Cooling
Jet skis produce a lot of heat, just like modern high-powered motors. Most jet skis employ an open loop cooling system to manage engine cooling, which makes use of cooler exterior lake or ocean water.
In order to absorb the heat from the engine, this external water circulates through the water jacket of the engine. The heated water is then released back into the body of water where the vessel is working.
A closed loop system, like one seen in an automobile cooling system, is used by Sea-Doo personal watercraft. The heat exchanger used by these crafts. The heat exchanger functions similarly to an automobile radiator, except instead of cooling the engine coolant with outside air, it does it with outside ocean or lake water.
Rooster Tail
When operating, Yamaha WaveRunners emit a spray of water into the air known as a “Rooster Tail.”
Contrary to popular opinion, the rooster tail serves largely as a safety precaution. This jet of water is not hot water leaving the cooling system, as is generally believed. Because they are much smaller than boats, personal watercraft sometimes require abrupt direction adjustments when being operated. The rooster tail lowers the possibility of an accident by assisting other boaters in seeing the smaller ship.
This idea is comparable to the usage of high flags when riding ATVs and dirt motorcycles in extremely mountainous terrain, such sand dunes. Some of the water leaving the propulsion channel escapes the WaveRunner’s back deck, sometimes as high as 20 feet, to create the rooster tail.
Open Loop Cooling Vs Closed Loop Cooling
One of the most frequent debates in the pwc world is whether to use closed loop or open loop water cooling. The main reason behind this is that whereas the majority of other manufacturers (Yamaha and Kawasaki) employ open loop, Sea Doo is the main user of closed loop.
The dispute over which is superior is closely related to the Sea Doo vs. Yamaha vs. Kawasaki controversy, which is unquestionably one of the most popular topics of discussion among pwc fans.
What Is Engine Loop Cooling?
Large quantities of heat are produced by any motor, whether it be on a jet ski, boat, or automobile. It doesn’t take long for an engine to overheat and stop working if there is no cooling system in place. Once this takes place, a myriad of issues follow.
There is often some sort of cooling mechanism in place to stop an engine from overheating. Engine cooling systems come in just two basic varieties: air-cooled and water-cooled.
Heat is dispersed by a fan or by simply using natural circulation in air conditioning systems. Any vehicle that has a hood scoop”a hole in the hood”is almost certainly air-cooled. The engine is cooled off by the hole’s airflow, which is directed at it.
Air conditioning is frequently used on non-marine vehicles, however it is ineffective on jet skis and other personal watercraft. In general, jet ski engines don’t have enough air-exposed surface area to allow for adequate cooling. This is mostly caused by the ergonomics of jet skis, which cannot simply be adjusted. Jet ski engines will likely remain water cooled for the foreseeable future until air cooling technology is developed.
When air cooling is not an option, water cooling systems are an excellent method to keep an engine cool. Water cooling disperses heat from the engine similarly to air cooling but using water. Water cooling systems come in two flavors: open loop cooling and closed loop cooling. This is where the debate between open loop cooling and closed loop cooling begins.
Open Loop Cooling
Pros Of Open Loop Cooling
The most effective sort of water cooling system is often one with an open loop. It operates in a fairly straightforward manner yet is nonetheless incredibly powerful.
To cool the engine, water from around the jet ski is drawn up and run through the system. The technique is by no means difficult, and many Sea Doo owners even switch their boats over to open loop.
Because they require a lot less upkeep than closed loop systems, proponents of open loop systems favor them. Because no additional fluids are required, owners will have one less thing to worry about.
Cons Of Open Loop Cooling
Open loop cooling systems have certain potential downsides even if they are the most effective.
The main defense used by proponents of closed loop cooling is that running the system with raw water might lead to maintenance concerns.
A pwc with open loop cooling circulates salt water continuously through the system when it is utilized in a salty area. Owners must put fresh water through the system after each usage to halt corrosion. Despite the fact that there are cases of individuals not cleaning their jet skis after using them in the ocean for more than five years without any issues, it is not advised.
The risk of debris being sucked up into the engine is another reason against open loop cooling systems in addition to the danger for saltwater corrosion. Despite arguments against open loop cooling, it happens relatively infrequently. Although there is a possibility, the majority of owners never have any issues with debris being drawn into the engine.
Remember that open loop cooling systems are employed by 99% of boat manufacturers. That wouldn’t be the case if they weren’t effective.
Closed Loop Cooling
Pros Of Closed Loop Cooling
Though often more complex than an open loop system, a closed loop cooling system can nevertheless be a very efficient cooling technique.
Similar to open loop cooling, closed loop cooling cools the engine using the ambient water. The key distinction is that the boat never gets wet. Instead, a riding plate’s interior is surrounded by a circle of hot antifreeze, which transfers heat to the water around it. The riding plate is able to transmit heat from the engine and into the water since most rivers are considerably colder than the engine.
Sea Doo is now the only producer of personal watercraft to use closed loop cooling systems. They formerly employed open loop cooling, but they have now switched to pwc throughout their whole product range. As a result, the argument between closed loop cooling and open loop cooling began.
Cons Of Closed Loop Cooling
Compared to open loop cooling, closed loop cooling has certain apparent benefits, but it also has significant drawbacks.
The most common defense used by critics is that it needs more upkeep. Fluids that are suitable for closed loop cooling systems are required for proper operation. For the owner, this entails extra effort and trips to the dealership. Additionally, the intercooler and exhaust are not sealed off in closed loop systems. As a result, while winterizing, the exhaust and intercooler should be purged.
Closed loop cooling just isn’t as efficient, according to open loop proponents, who also make this argument frequently. It is significantly more difficult to distribute heat when the riding plate is used instead of letting the water do it naturally.
The last disadvantage is that damage to the riding plate can happen easily when beaching, which is usually mentioned. Obviously, utilizing a jet ski anchor to hold it out a few yards can prevent this, but that isn’t always an option. The riding plate may sustain damage over time if beaching is a frequent activity. Numerous additional issues arise quickly after the ride plate is harmed.
Open Loop Cooling Vs Closed Loop Cooling ” Which is better?
The controversy between Sea Doo, Yamaha, and Kawasaki gave rise to the overall open loop vs. closed loop cooling dispute. The choice between the two cooling systems isn’t nearly as complicated as people make it out to be. There are advantages and disadvantages to each, of course, but most pwc manufacturers produce models that are quite dependable.
The cooling system shouldn’t be the deciding factor in someone’s choice. A corporation would probably no longer be in business if their boats weren’t dependable and efficient. A single phase in the purchasing procedure is deciding which system is superior. Many more factors also need to be taken into account. The importance of features and pricing far outweighs that of a cooling system.
Which of the two is superior cannot be determined with absolute certainty. Both methods have benefits and drawbacks. Individuals must finally determine for themselves which of the two is superior.
