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7 Reasons Why Your Jet Ski is Bogging Down [+ Fixing Guide]

7 Reasons Why Your Jet Ski is Bogging Down [+ Fixing Guide]

There can be many reasons why your jet ski is bogging down, but the most likely ones are as follows:

  1. Clogged Jet Pump
  2. Clogged Air Filter
  3. Fuel Line Issues
  4. Carb or Fuel Pump Malfunctions
  5. Wrong or Dirty Fuel
  6. Waterbox is Filled with Water
  7. Other Engine/Exhaust Issues
If you want to find out more about these malfunctions and their remedy, this post is for you.

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

7 Reasons Why Your Jet Ski is Bogging Down

1. Clogged Jet Pump

Although a clogged jet pump can’t cause the engine to actually bog down, it may produce similar symptoms.

A stuck rock or wood stick in the pump can block the engine since the impeller is connected to it by the direct drive shaft.

This is why you should first check and clean the intake and the jet pump before doing anything else.

If they are completely clean but your ski is still bogged down, keep reading!

2. Clogged Air Filter

Most production jet skis feature an air filter nestled in an enclosed air box.

Even though jet skis run on the water, which is a fairly clean environment, the air filter is prone to collecting dirt and clogging over time.

You may want to check and clean out the air filter and make sure that the air box is properly attached to the hoses.

3. Fuel Line Issues

Fuel line issues can also cause your jet ski to bog down. Consider inspecting and cleaning key elements of the fuel line, including:

  • Fuel lines
  • Fuel vent valve
  • Fuel selector switch
  • Fuel filter
Fuel line issues are common problems, especially on vintage 2-stroke jet skis that still feature the original fuel lines.

Aged fuel lines are prone to cracking, resulting in an air leaks. Their material can also deteriorate and clog the fuel filter or the carb.

Inspect and replace the lines if necessary, just like the clamps and connections.

Consider cleaning the fuel filter and taking a closer look at the fuel vent valve and the fuel selector switch as well.

4. Carb or Fuel Pump Issues

It’s safe to say that the most common cause of jet ski bogging issues is carburetor problems. Unlike their modern counterparts, most 2-stroke jet skis utilize carburetors, which can go wrong in many ways.

Therefore, if you have a carbureted 2-stroke ski, you should check its carburetors. Early models featured only one carb, while the more advanced machines had 2-3 carbs depending on the number of cylinders.

First, you may want to check and adjust the carbs, since improper carb settings can lead to an inefficient air/fuel mixture.

Surprisingly, a jet ski can bog down even if its engine is running lean (too much air) or even rich (too much fuel).

If your carb settings look good, then the problem could be caused by a clog in the carburetors.

Consider taking the carbs apart and cleaning their internals including the jets, passages, and internal carb filters. If the gaskets and the internals are worn out, maybe it’s time to rebuild the carbs.If you have a fuel-injected 2-stroke or 4-stroke jet ski, it’s more than likely equipped with a fuel pump and injectors.

Just like the carbs, these components can also clog or break, causing bogging issues.

5. Wrong or Dirty Fuel

Even if your fuel system looks good, don’t forget that using the wrong type of gas can also cause the jet ski to bog down.

Old gas is prone to gumming up in the tank or the carbs, but water or dirt in the gas can also cause various clogs and issues.

Also, make sure that you use the appropriate gas octane stated in the operator’s manual. If you have a high-performance supercharged jet ski, don’t forget that it requires premium gas.

If you have an older 2-stroke machine, make sure to use the right oil/fuel ratio.

6. Waterbox is Filled with Water

It’s a lesser-known fact that a jet ski can bog down if its waterbox is filled with water.

The waterbox is a metal box that is part of the exhaust system. If it’s full of water and you hit the throttle, the engine will bog down since it trying to clear the water out of the box.

The water will block the way of the exhaust gases and won’t allow the engine to breathe.

7. Other Engine or Exhaust Issues

Unfortunately, jet ski bogging issues can be also caused by a more serious engine or exhaust malfunctions, including:

  • Low compression in the cylinders
  • Ignition issues
  • Missing gaskets
  • Cracked manifolds
  • Unsecured carb connections
  • Unsecured exhaust connections
  • Exhaust leak
  • Collapsed exhaust pipe
Do a detailed inspection of your exhaust system and engine to rule out these possible errors.

It’s also recommended that you warm up the engine before you start hammering the throttle!

Conclusion – Why is Your Jet Ski Bogging Down?

There’s no question that the main reason why a jet ski may be bogging down is fuel delivery issues.

Too much or too little fuel can cause various engine malfunctions, and “bogging down” is one of them.

These issues are often generated by a fuel line or carburetor/fuel pump issues, or even a clogged air filter.

Make sure that the fuel lines and the carburetors (or fuel pump/injectors) are clean and working properly, and that the gas tank is filled up with the appropriate fresh gas.

If the problem still exists, you should take a closer look at the engine and the exhaust system, since air/exhaust leaks, low cylinder pressure, or wrong ignition timing can also cause bogging issues.