New Owner 195 news some feedback

[JetBoat195G]

The black sealant sticking out sure does seem odd. Perhaps that's the issue. You don't see anything like that in Luc's picture, and I don't recall seeing anything like that in the inlet to my impeller. I wonder if too much sealant was applied there, or if the black seal forward of the yellow wear ring somehow got damaged when the jet pump was originally installed on the boat. Just speculating..... If there's another Scarab at the dealer, you could peek into their jet pump inlet for comparison.

 

[Luc Lafreniere]

Definitely too much sealant. Hence the suggestion to clean it up. But that's an easy fix.

@Pablo I repeat, do NOT try and remove the intake grate! lol I mentioned before, I say again, do NOT remove the intake grate! It's held by bolts and a nut UNDER the engine. The nut side is sealed with a sealant to prevent water from getting into your boat. You CANNOT hold that nut while spinning the bolt from under the boat. This means the nut spins on the inside and breaks the sealant. Now you have a slow leak and it's very, very difficult to re-tighten and re-seal it since it's UNDER the engine.

If you choose to access the pump now or in the future, you MUST do it from the stern of the boat. It seems complicated, but it's a very easy procedure. Here's a video on how to do it:

Different brand of boat, identical jet engine and same procedures to remove it. I can do mine in about 10-15 min.

But I'd wait on the dealer before going through all of that.

 

[Pablo]

Great idea I will share the observations with the dealer and inspect boats on the show room

thanks!!!

 

[Luc Lafreniere]

To add to @JetBoat195G , yes, that excessive sealant can cause water perturbations which can cause cavitation. This could indeed be the cause of the high RPM vibrations. Only one way to confirm that. Trim the black sealant so it's nice and clean and go boating! lol

 

[Pablo]

Thanks Luc for saving my ass!

 

[Luc Lafreniere]

You aren't the first... lol Another few pro tips completely unrelated.

1. Do NOT ever run the engine out of water for more than 1 min at a time. The shorter, the better. There's a very important seal that can overheat and then your boat will leak.
2. If you connect water to the flush port to flush your engine or antifreeze to winterize it, the order you do it is very important too. Engine on, water on, water off, engine off. IN THAT order. You must never have water pressure unless the engine is running. Otherwise it's possible to get water inside the engine. Long story. Just follow this.
3. If you get towed in the future for whatever reason, go very slow. That's pretty typical when being towed anyways, but make sure of it. If they tow you fast, water pressure buids inside the jet pump with water flowing through. This can push water into your exhaust system (as designed) but since the engine isn't running, water can travel all the way into the engine once again. Going slow solves this. Alternatively, Rotax recommends you clamp a specific hose to prevent this from happening. I can provide you with diagrams and what tool you need for that later. Don't worry about it right now. Deal with getting your boat working and on the water again. We can discuss more in the future.

Hopefully those 3 (plus the other grate comment) will save you from damaging your boat. They are the most common mistakes in my opinion that I keep seeing.

 

[Pablo]

Luc are jet pumps high maintenance? You do the work yerself?

 

[Pablo]

Thanks sir. So is it the impeller that wears or is it the bearing that’s replaced

 

[Pablo]

Fortunately I am 100% on local lakes so I foresee no need to flush the boat on the trailer. The towing can happen any time so that’s great information. These are 3 cyclinder engines and they rev up pretty high. Does that hurt them if running at the high rpms. Unlike V8’ you typically don’t run those above 4K

 

[Luc Lafreniere]

Jet pumps and Rotax engines are super LOW maintenance AND you can do it yourself very easily. I've been doing all my maintenance and I'm at over 240h now. If you want to do this, I can help guide you one on one. It's really simple, even I can do it.

The impeller does NOT wear, the wear ring does. That's how they are designed. Wear rings are cheap to replace, but I've never had to replace mine. All depends on if you suck up debris and what. Impellers can get nicked though... etc. But generally, they last a very long time.

RPMs are generally high for jet boats, hence the extra noise. They are designed for it. But like any engine, if you run at 100% all the time, there's always more wear. I don't worry about that too much. But there's always less wear at whatever your ideal speed is for max fuel efficiency. That's always where your engine works the least hard for max distance.

 

[Pablo]

Ok thanks. My wife rode a Spyder F3 Rotax powered. Very smooth

 

[Pablo]

Hi Luc,

well I dropped off the boat to the dealer and they were very understanding of my concerns. I share the observations and recommendations of what the issues may be. They will keep the boat and check the pump, muffler, engine alignment and water test it. In fact they stated they will do the remaining 2.5 hrs break-in and recheck check. Can’t ask for anymore than that. Thus far very pleased with the service and willingness to resolve the problems.

Regarding excessive engine noise, they will research with factory to see if there is additional sound proofing material to wrap the muffler. Thanks again to you and everyone that contributed. I will let you know the results. Fingers Crossed!!!

 

[Jim_in_Delaware]

@Pablo, please report back to us what the dealer finds.

It is gentlemen, like @Luc Lafreniere, who make this forum what it is. I know that if experienced folks weren't so helpful, I would not even be considering purchasing a jetboat!.

Jim

 

[Pablo]

Jim you are spot on. I was seriously considering asking for a refund. Luc was extremely helpful. When I visited the dealer (3 hrsdrive) I was full of questions and suggestions because of Luc and Jetboaters.

I am hopeful the dealer will remedy my concerns. I did find some “over the counter” marine sound dampening blanket material. If I am not happy with the sound I may give it a try and wrap the muffler

thanks for the note Jim

Pablo

 

[Luc Lafreniere]

Appreciate the kind words guys. Glad to hear the dealer looks good and will take care of you. Especially after a 3h drive. I'll echo @Jim_in_Delaware 's comments, please report back once they tell you anything. Many such threads never get a final report and future people are left hanging. lol

 

[Pablo]

No worries Luc,… I will!

 

[JetBoat195G]

Just thought that I would post a picture of my impeller inlet, so that you could have a visual comparison. (2019 195G)

A few comments on noise. My previous boat was a sailboat, so I was concerned about the potential noise as well. I find it to be less of an issue than expected. When you’re motoring at 25mph, the wind offsets the engine noise to some extent. However, my wife and I have a tendency to do more anchoring and drifting and watching the world go by, and then there’s no noise.

 

[Pablo]

Thanks for the valuable and practical comments. I also sailed and always enjoyed the sound of the wind vibrating the shrouds! Then You knew you were hauling ass?

well my main concern now is vibration. There is an annoying high frequency vibration at around 6k that I can literally feel from my feet to my butt! Something is either not aligned or out of tolerance. The boat acts like a giant speaker and everything including noise and vibration resonates. I am hopeful the dealer will sort out the vibration

concerning noise, I have researched marine sound proofing matting materials that can supplement the existing materials so I will probably experiment a bit

lastly,.. engine sound becomes “noise” when the sound is not pleasing. I have had high performance ski and offshore boats with single and twin V8’s. The sound is awesome, it’s become a feature and people love it and mostly because it’s pleasing even though it may be the same db . If I were Scarab I would engineer creating a better exhaust note! A better sound would offset the “noise” concerns. Motorcycles, trucks and cars have mastered this with either deliberate engineering ie the Harley Davidson motorcycle or aftermarket exhaust options that people pay for. If they could make a 3 cylinder high rev motor sound pleasing? Concerns would diminish!

 

[Pablo]

Last comment, if I were Scarab or Yamaha I would encourage the after Market motorcycle muffler mfg’s to create a DIY replacement. They are skilled on small engine exhaust. I would also suspect that Rotax in other of their applications with motorcycles, racing and experimental aircraft also has solutions in hand

 

[Pablo]

Just thought that I would post a picture of my impeller inlet, so that you could have a visual comparison. (2019 195G)

A few comments on noise. My previous boat was a sailboat, so I was concerned about the potential noise as well. I find it to be less of an issue than expected. When you’re motoring at 25mph, the wind offsets the engine noise to some extent. However, my wife and I have a tendency to do more anchoring and drifting and watching the world go by, and then there’s no noise.

Did you experience any high frequency vibration at higher rpms? We did and could feel it from the floor to feet and butt.