How to do a Sea-Doo Coolant Flush on a 4-TEC Jetski

Seadoo battery coolant flush

How to do a Sea-Doo Coolant Flush on a Jetski

A Sea-Doo Coolant Flush on a 4-TEC Rotax engine is a lot like a modern car engine. It uses Type A coolant to keep the engine at the correct operating temperature. If you haven’t replaced the green coolant in over 200 hours or 2 years its time to get it done.

My Sea-Doo GTI jet ski coolant was well overdue at 3 years. Coolant will start to lose its anti-corrosive properties and fail, so best to get it replaced at manufactures recommendations.

Replace Sea-Doo Coolant

Now you can take your Sea-doo 4-tec to your local dealership, and start handing out your hard-earned cash, or you can do it yourself. The Jet-ski coolant flush should only take around 20 minutes. Your owners guide manual will say, it has to be done by the dealer, but it is really easy to do it yourself.

Sea-doo coolant flush drainFirst, run into your local auto supply store and pick up some Type A Coolant, usually made of Ethylene Glycol together with some protective additives. It is mixed with water to produce coolant. You can either get the ready mixed stuff or the concentrate and mix our own with Demineralised water, 50 – 50 mix.

5 Liters will be enough to completely change out your jet-ski coolant.

I always use Calibre Anti-Freeze/Anti-Boil Type A, 5 years or 250,000km protection here in Australia. If you would like the official Genuine BRP (Ski-Doo, Sea-Doo, Can-Am) “Red” pre-mixed antifreeze/coolant. Then you can get it from Amazon.

It comes in 1-liter bottles.

Sea-Doo Coolant Flush Procedure DIYSea-doo coolant drain bolt plug location

  1. Remove the coolant pressure cap from overflow plastic tank.
  2. Carefully remove the stainless drain plug from the bottom of ride plate using a hex Allen key and drain into a container. Do this where spillage won’t matter.
  3. Pour demineralized water into overflow tank and flush out any remaining coolant. When it’s finished draining pour a 50/50 mix into the overflow tank.
  4. Have someone watch the drain plug as you pour the mix in, as soon as there are no air bubbles, screw in the drain plug. This is optional but helps not having to re-top up coolant next time you go for a ride.
  5. Fill the overflow tank to the correct line. Not too much, too little.
  6. Replace overflow coolant tank cap.
  7. If you have a torque wrench torque up the drain plug – 75lbf.inch
  8. Run Sea-Doo jet ski engine for 30 seconds, and recheck coolant level. Top up if required.
  9. Failure to flush and top-up your cooling system can cause your boat, jetski or car to overheat.

Thanks to 3ftDeep for this detailed Sea-Doo Coolant Flush procedure

What Can Go Wrong – Snapping a Bolt or Screw

For some reason, the hex stainless drain bolt for the Sea-doo is made out of butter. Not sure if it’s a bad batch or bad design but there are a few cases or people snapping off the heads of these bolts. Possibly being over tightened at the Sea-doo factory or at the dealer if your coolant has been changed out before.

broken seadoo coolant drain boltI was very aware of this issue and I even managed to break off the head of my drain bolt.

So how do you get out the snapped bolt? Well there are a few devices made to help with broken bolts but the 2 that are very common are:

Easy Outs, SpeedOuts,  Damaged Screw Extractor & Bolt Extractor Set

 and Left Handed drill bits.


Everyone should have these in their toolbox.

How to Remove a Broken Bolt on your Sea-doo

First, centre punch the center of your broken Sea-doo bolt. This will help your left-handed drill bit get a good start in life. The stainless is a very hard metal so take it slow.

Use you drill on slow speed first to start drilling. If you are using a left-handed drill bit make sure the drill is in reverse. If using only normal drill bits you want to run forward direction. Be careful on bolts that go into a cavity.

The Sea-doo drain plug stops fluid from coming out. There is nothing stopping the bolt from traveling into the center of the ride plate cooling reservoir if the bolt head snaps off. Be careful if using normal drill bits to dill out the broken bolt, because if running forward direction and the drill bit catches, you will wind the drain bolt all the way into the ride plate. You will never get it out.

Most times the bolt will self-wind out if using a left-handed bit. If it won’t, once you have drilled in about 1 cm you can use this Easy Out from Amazon, Job done.

Continue With your Jet Ski Service

Now that you have done the coolant flush why not continue with doing a Sea Doo oil change. It’s easy and won’t take too long. Think of all the money you have now saved now go out and have fun in your fully serviced toy.

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9 months ago

Well on attempt to torque to 75 lbs drain bolt snapped on me as well. Can’t seem to find anywhere what size bolt that is. Any info would be great.