Dry start smoke

Note: This site contains eBay affiliate links for which SeaDooForum.com may be compensated
Not open for further replies.


New Member
smoke and anitfreeze on dry start

I just bought a 2004 sportster 155 4-tec. I've been reading that you can dry start these boats for 2-5 mins with no worries of over heating. So, I got impatient today and just had to hear her run. She started on the first turn and I let her run for 30-60sec keeping an eye on the coolant reservoir(levels didn't budge) when I noticed a thick grey smoke coming from under the back. It didn't look like typical exhaust. I turned it off and looked under to the back to find antifreeze dripping off the black underplate. No sign of any antifreeze in the engine compartment. The boat was winterized by a seadoo dealer. So, I'm wondering If this is just antifreeze that was flushed through for the winterization or have I done something wrong.

Also, before starting the season should I replace the antifreeze that was put in for winterization with 1/2water, 1/2 antifreeze or should I just leave in what's in there?
Last edited by a moderator:
Somebody who knows more, feel free to chime in ....

The anti-freeze you see is comming out of the exhaust system on the engine cooling system. I believe there should be a connection near the pump. Attach a garden hose to flush the exhaust system. This is the same place where antifreeze is added during winterization. When you started your ski, this is what you saw coming out, completely normal. The smoke ... not sure on that one.

I have the same boat as yours so I will help sort things out and try to answer your questions.

First, although you can run these boats out of water on the trailer for 2-5 min. they must be hooked up to a garden hose to supply cooling water to the exhaust. Read the owners manual and you will find detailed instruction on how to do this. You should be able to download the owners manual here from the forum or even the seadoo website. Since you ran the motor dry for only 60 sec., I doubt you damaged anything but I wouldn’t make a habit of doing this without hooking it up to a hose.

In short, there are 2 separate cooling systems for the 4-tec engines. The closed loop cooling (green anti-freeze) is for the motor itself only. The second cooling system uses lake / seawater (or a garden hose if out of water) to cool the exhaust system. Running the engine without cooling to the exhaust will melt the exhaust hoses very quickly. This is generally the case with all boats not just seadoos.

As for smoke coming out from under the boat I am not sure I understand where you saw this smoke. If it was coming out the exhaust port, then it was probably just steam which is normal. The coolant dripping from around the jet pump is probably normal, as others have suggested, and is just dripping out from winterization.

For pre-season maintenance on this new-to-you boat I would go through everything unless you have previous owner’s maintenance records. The main items should be (but there are also many other minor things to check as well):

Clean engine cooling system and replace coolant
Oil and filter change
Spark plugs
Service jet pump to make sure things are working well

I have learned a lot from the forum and from detailed reading of the shop manuals over the past year. Definitely not an expert yet, but able to finally chime in on the few things I do know. I’ll be going through the same maintenance procedures very soon this spring as well.

Hope this helps a bit and I’m sure others can add info where in case I missed something. Search the forum a bit more and I sure you'll find lots of information about maintenance / winterization / pre-season checks. If you are reasonably mechanically inclined and read the shop manuals all the above mentioned tasks should be projects you can do yourself with the right tools.

Good luck to you and enjoy the new boat, they are a blast!
Thanks guys
I think more than anything I was being paranoid. I had in out on the water a feW day ado and everything was running perfect. Fun little boat. I think the antifreeze was just part of the winterization and the smoke was due to fogging on winterization. However, I'll be hooking it up to the hose for any future dry/trailer starts.
Thanks again
Last edited by a moderator:
I forgot to mention that when you hook the boat up to the hose it is very important to never have the hose turned on without the engine running, or you could very quickly fill it with water - which would be very very bad.

Correct procedure:
1. start engine
2. turn water on
3. turn water off
4. turn off engine

Not open for further replies.