Excessive exhaust/Exhaust rolling into the cockpit

[Murf'n'surf]

Atmospheric conditions including humidity and temperature may affect this testing. @ScarabMike you should run a test at the same speed as @Dan Hops and see if the vapor cloud comes up the stern. Even considering all of the possibilities, it sure seems like @Dan Hops boat is having emissions issues.

 

[Julian]

That doesn't look right at all....

 

[BoaterGuy]

Atmospheric conditions including humidity and temperature may affect this testing. @ScarabMike you should run a test at the same speed as @Dan Hops and see if the vapor cloud comes up the stern. Even considering all of the possibilities, it sure seems like @Dan Hops boat is having emissions issues.

I've seen that same smoke in the test videos from boat test and other scarab videos. I would say the smoke is normal, but that doesnt mean it's right.
(3:01)

You can see it on the Chap boats as well:
(2:31)

 

[itsdgm]

Sorry to hear about your issue @Dan Hops. I don't know much , if anything about the Scarab boats, but looking at your video leaves me wonder if you have something obstructing/deflecting the flow of your jet nozzle. It seems as if water exiting the pump is being redirected upward causing it to hit your heat exchanger and probably picking up exhaust gases too. Then the mist is getting sucked back into the boat. Do you have any fins or mods added to the rear of the boat? Pics? Good luck, hope you get it figured out soon!!!

 

[ScarabMike]

Here is some more info about the exhaust and cooling system on the modern Rotax engines...

Sea-Doo uses a heat-exchanger inside the ride plate to allow for a closed-loop cooling system. A 50/50 anti-freeze mix in the engine can now run at 87C for best power and emissions without the risk of sand or silt deposits building up in the engine's cooling passages. Sea-Water is used for cooling only in the exhaust system and intercooler. When the craft is stationary with the engine running the ride plate is submerged so there is sea water on all sides to ensure maintaining engine temperature. At planing speeds there is sea water only on the underside of the ride plate, but it is flowing past at boat speed, up to 110 kph (68 mph), so there is plenty of cooling capacity.
PWC's used to have a reputation for being noisy, but that was many years ago. Today they are amongst the quietest of all boats. Sea-Doo uses dual water cooled aluminium mufflers for very quiet operation. Water is injected into the first muffler, dropping the exhaust gas temperature and engine exhaust sufficiently for it to be carried through the exhaust system's rubber hoses without damage. The water cooling also has the added benefit of keeping the system carbon free and clean (steam cleaned!).

You may have either a clogged muffler, or there may not be enough water mixing with the exhaust to keep it at a cooler temperature, this would build up more steam, and it would also not clean enough of the CO2 coming out of the exhaust port next to the jet.

 

[Murf'n'surf]

Here is some more info about the exhaust and cooling system on the modern Rotax engines...



You may have either a clogged muffler, or there may not be enough water mixing with the exhaust to keep it at a cooler temperature, this would build up more steam, and it would also not clean enough of the CO2 coming out of the exhaust port next to the jet.

Good point. I believe he is in Canada where the water can't be warmer than 60F.

 

[MikeyL]

That looks and seems legit to me. But @Dan Hops doesn't. There HAS to be something wrong there...it happens unfortunately. I'm sure it's fixable if you find someone willing to do the right thing.

X450 on what @Glassman wrote.

 

[RiverRat]

I thought it was interesting that Scarab posted this on their Instagram today.

 

[Murf'n'surf]

That's interesting!?!?!

 

[ScarabMike]

LOL

 

[Scottintexas]

@Dan Hops wondering if you were able to get this figured out yet?

 

[Dan Hops]

Still working through it with rec boat holdings.

 

[Jetboatgirl]

Hey guys, has anyone had any type of resolution when it comes to steam/smoke?

I've never had a steam/smoke issue before now. I just got back from an evening boat ride and on my way back, I noticed it was smoking. My boat has 35 hrs on it and it primarily steams/smokes when the boat is in neutral or idling.

Any help would be great!

 

[ScarabMike]

@Jetboatgirl Its a common occurrence with these boats.

 

[Jetboatgirl]

So is this something I should bring up to the service department at my local dealership? Is there a fix to it or do I just have to live with it?

 

[ScarabMike]

@Jetboatgirl Its normal. You can have the dealer check the waterflow through your exhaust, but if there is water coming out of the exhaust port when you flush, 9 out of 10 your good to go.

 

[Murf'n'surf]

The only time the exhaust comes into the cockpit is if the wind is blowing it faster than you are traveling. It's common among all boats at a slow speed.

 

[Dan Hops]

Having spent the summer dealing with my issue i'll sum up the outcome. My video shows what happens with the steam/exhaust when running my boat. I've noticed that it roles into the boat more when running with the wind. This happens at anywhere from 18 mph to top speed. My boat has 78 hours on it and water temp on our lake is high 70's. After many visits to my dealer, which have been great to me, I was able to get Al Sturch from BRP in my boat to test CO levels. I have the spreadsheet report on the findings. All within reasonable levels. My dealer also let me take out a brand new 2015 and do comparable testing. Boat performed the same as mine. Maybe a little less smoke.
That being said, I still believe there is an issue with these boats, or mine at least. I have owned a Sea doo 180 challenger and had never experienced exhaust/steam like I do in the Scarab. One thing I did notice is that Scarab have changed the location of the exhaust port in the hull. Is this a design problem? I think so. But i'm not an engineer and have no idea how to prove this. I believe this creates a larger than normal vacuum effect.
So that's where i'm at now.

 

[Scottintexas]

I don't know what your exhausts look like but I wonder if you could put an extension on it to direct it into the water like some of the outdrives have to prevent CO problems.

 

[Slugger55]

I have never had an issue like @Dan Hops is having. @ScarabMike and I ran our boats in Panama City last summer and never saw anything like your video shows. Maybe a super charger issue?