How to Properly Warm up a Jet Ski [Full Guide]

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Powersport vehicles must be warmed up before each ride, and jet skis are no exception. Lack of warming up puts a lot of strain on the engine, resulting in excessive wear and less durability. The engine can suffer severe damage like a cold seizing in the worst-case scenario.

If you want to avoid these issues and keep your ski in good shape for the long run, this post is for you.

We at JetDrift have compiled all you need to know under one roof!

Do you Need to Warm Up a Jet Ski?

Jet ski owners are prone to immediately hammering the throttle as soon as their skis hit the water. But let’s face it, this is completely wrong! Lack of warming up may end in various malfunctions, including an engine seizure.

To avoid these issues and keep your jet ski in good shape, it’s highly recommended to warm up the engine before each ride.

But why is warming up a jet ski so important?

The first and main reason is because the metal parts will expand.  

Jet ski engines are known for their high performance, which generates excessive heat. And as we know, metal engine parts expand when heated.

The bearings, pistons, rings, cylinder walls, and other engine internals are completely cold when you first fire up the engine.

The optimal clearances of these parts are only assured when the engine reaches its normal operating temperature. If you start to hammer the throttle on a cold engine, the internal engine temperature can quickly rise due to inadequate clearances.

Subjecting these parts to this extreme heat without warming them up in advance can cause them to expand and intensively scuff.

The pistons are especially prone to warming-up and expanding faster than the cylinder walls.

The pistons, which are small pieces of metal, move up and down in the cylinders, which consist of a much larger mass of metal. As you can imagine, the pistons will warm up much faster.

This results in excessive wear and tear or major engine damage like a cold seizure.

Besides the potential for engine damage, many other parts can break due to not being warmed up, like exhaust pipes and superchargers.

Regarding 4-stroke jet skis, another reason why their engines have to be warmed up is oil temperature.

Low engine oil temperature ensures worse flowability resulting in poorer lubrication. The lack of oil produces more scuffing and can even cause something to break.

This is where the warm-up procedure comes into play; it helps warm up the engine oil and deliver it wherever it’s needed.

If the ski has been sitting for a while, most of the engine oil returns into the oil pan leaving many parts unlubricated. Warming up the engine ensures that engine oil reaches all of these parts.

On top of that, a jet ski engine burns less fuel and performs better at the optimal operating temperature.

It’s a lesser-known fact that certain models’ ECU (main computer) allows full engine power only between a certain temperature range.

A warming up period also provides an opportunity to make sure that your ski is running well. There isn’t anything much worse than riding far from the shore before realizing that your ski has some issues.

Moreover, warming up the jet ski is particularly important in certain cases like after an engine rebuild, after de-winterizing, and during the break-in period.

How do You Warm Up a Jet Ski?

Despite its importance, owner’s manuals usually don’t even mention the warming-up process.

For your convenience, we at JetDrift have compiled the basic steps on how to warm up a jet ski:

  1. Start the engine when the ski is in the water
  2. Run the engine at idle for 1-2 mins near the dock
  3. Ride at no-wake speed for a couple of minutes
  4. Get it up to plane very carefully
  5. Cruise at 35-40 mph for 5-10 mins (avoid WOT accelerations)

The key is never hammering the throttle before the engine has reached its operating temperature.

Best practice is to start the ski and let the engine idle for a couple of minutes before heading out.

It’s a great time to put sunscreen on or finish other preparations. This way, you won’t waste time – but you will likely save your engine.

In most areas, there’s a no-wake zone around launching ramps and docks, which you have to go through before getting out into open waters.

Riding through these zones is also an important part of the warming-up process, as here the engine is already running under a moderate load.

But even if there isn’t a no-wake zone around your dock/ramp, it’s highly recommended that you ride at 5-7 mph during the first couple of minutes.

Then, you can start your ride! Increase your speed and carefully get the machine up to plane with minimal throttle.

In the next 5-10 minutes, you shouldn’t exceed half throttle, and you can’t go wrong by cruising at around 35-40 mph. You should carefully vary your speed while avoiding race-like accelerations.

After this light cruising, you can be sure that your jet ski is now perfectly warmed up!

This may seem too excessive for some, but don’t forget that jet skis have high-performance engines that feature very tight tolerances. Therefore, they have to be carefully warmed up.

How to Warm Up a 4-Stroke Jet Ski

As a rule of thumb, it takes longer to warm up 4-stroke jet skis than their 2-stroke counterparts.

Why?

This is because the engines on 4-stroke jet ski are much heavier, so they need more time to reach their operating temperature.

What’s more, their engine oil has to be warmed up as well, which takes additional time.

As a rule of thumb, a 4-stroke jet ski can take 10-15 minutes before its engine and oil reach the optimal temperature.

How to Warm up a 2-Stroke Jet Ski

Unlike 4-strokes, 2-stroke jet skis warm up much faster. On the other hand, letting these machines idle near the dock too long is not recommended.

Most 2-stroke jet skis feature oil injection, which causes the engine to run rich after a cold start. This rich environment can foul the spark plugs while idling, causing many headaches for the owner.

Therefore, if you have a 2-stroke, don’t let its engine idle too long. Instead, after a quick warm-up, slowly ride the ski while applying some throttle to clear the plugs.

Like with 4-strokes, don’t hammer the throttle before the engine reaches the desired temperature.

When do you Know That Your Jet Ski Has Warmed Up?

Unfortunately, there’s no hard number for how long you should warm up your ski, as it depends on many factors, such as:

  • Type and size of the engine
  • Number of cylinders
  • Type of cooling system
  • Environmental conditions

One of the major factors is the type and size of the engine.

2-stroke engines warm up much faster than their 4-stroke brothers. The size of the engine is no less important; the smaller the engine, the less time it takes to warm up.

Today’s jet skis are available with both open-loop and closed-loop cooling systems depending on the make and model. As a rule of thumb, it takes more time to warm up an engine with an open-loop cooling system as these power sources use cold external water for cooling.

And finally, don’t forget environmental conditions like the water and air temperature.

Are you wondering when your jet ski will be fully warmed up?

If your machine features a large digital gauge, it likely indicates the engine temperature.

In contrast, vintage jet skis are equipped with much simpler gauges. Be careful, as these gauges often display temperature figures, but they are typically for the outside air or the external water temp.

Although these skis don’t display the engine temp they do feature an “engine overheating light” and a beeper. Unfortunately, these devices can warn you if the engine is overheating but don’t reveal anything about the exact temperature.

If you have an old ski and want to monitor the engine temp, you may want to install an aftermarket temp gauge on it. This mod only makes sense if you have a strongly modified engine and want to keep your eye on the temperature.

If your engine is stock, you don’t have to stress too much about the engine temp. Just follow our guide outlined above to warm your ski up, and it should be fine.

Certain jet ski engines also idle at a slightly lower RPM once warmed up, so this can also be a clue that your ski is ready to go. Most skis are equipped with an RPM gauge, which is a great help in detecting this change.

What is the Optimal Temperature for a Jet Ski Engine to Run at?

As a rule of thumb, a jet ski engine should run at 160-180 Fahrenheit if it’s functioning properly. When idling, they typically run at 160-165 degrees, which increases to 170-180 degrees while cruising.

However, these are just basic numbers, as the exact temps vary depending on the features of the ski.

Engines with an open-loop cooling system usually run at slightly cooler temperatures, and the temperature varies much more than engines with closed-loop cooling.

In contrast, modified engines run at higher temps and are prone to overheating much easier.

Conclusion

Many owners are hopping on their jet skis and revving the engines to the limit right away – you can see this again and again around the ramps.

But let’s face it, this practice is completely wrong as it’s harmful to the engine in many ways.

This is because a jet ski has to be carefully warmed up before each ride.

A thorough warming-up process should include letting the ski idle near the dock for 1-2 minutes, and then a short ride at a no-wake speed should follow.

After this, the ski has to get up to plane with minimal throttle and cruise around for at least for 5 minutes at 35-40 mph.

Once the engine reaches its optimal temp, you can start hammering the throttle!

Jet ski engines typically run at 170-180 degrees Farenheit while cruising and 160-165 degrees while idling. However, these ranges may vary slightly, depending on the features and the engine’s performance.

Disclaimer: This post is for informational purposes only. Always check your owner’s manual and consult with your dealer about maintaining your jet ski.

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