Scarab 195 almost sank

[SandMan123]

I've had jet skis for a few years (Sea Doo GTR and Spark) and decided to buy a lightly used 2016 Scarab last week. Boat has 31 hours on it. Talked to the owner quite a bit and seemed like a nice lady, took meticulous care of the boat, not even a scratch on it. I took it out on the water Saturday with a boating friend of mine and after letting it warm up and idle out past the dock, the engine started to surge in forward and the check engine light came on. I called the owner, who told me that 2 years ago she had this issue and it was due to the fuel going bad over the winter.

So we pulled it out of the water and I bought a pump from Home Depot and removed about 25 gals of gas and put in fresh non-ethanol 91. Went out again, surging was better in forward idle then went away completely and check engine light went out.

I put about another hour of use on the boat without any issues, ran great. Then the family and I took it out again Sunday, wife, kids, etc. Youngest is 7. We were having a good time, anchored up for a bit, motored over to the middle of Oneida Lake (largest inland lake in NY, 20 miles long by 3-5 miles wide). I let my 18 year old drive for a bit - soon I noticed the stern seemed a little low in the water, and RPMs were above 6K to maintain 20-25 mph. Seemed a little weird so we stopped, and I checked the engine compartment. Water was gushing in through the small port next to the drive shaft. I started the engine again to get back to the dock and there was no thrust and a high pitched squeal like the drive shaft had stripped or something. I had this happen to one of my Sea Doos - twice in under 50 hours and the noise was the same.

There were no boats around and I had to call 911 and get the fire dept to tow us back in. The water level inside the bilge stabilized somehow, or stopped coming in, and it never got high enough to run the bilge pump.

Any ideas?? Is the driveshaft replacement something I could even tackle on my own?

 

[Luc Lafreniere]

To my knowledge, there is no port there. Only the through hull hole that allows the drive shaft to exit the boat and drive the impeller.

It really sounds like the water is coming in from the contact point between the drive shaft and the so called carbon seal. That contact point is very important (as you're discovering).

Possible issues include:

- Misaligned drive shaft/engine. This requires a proper alignment tool to ensure the drive shaft comes out correctly in the middle. Otherwise, it can cause excess friction on one side of the ring and wear it out.
- One of the most common issues is a user, running the boat outside of water for extended periods of time. The official number is no more than 2 min at a time, most of us don't do more than 1 min. There is NO cooling to this carbon seal when you're out of water regardless if you connect a water source the the flush port. The flush port only cools the exhaust system. There are numerous warnings in the manual to not run it too long outside of water. When someone does this, it causes excess heat/friction and again, wears out that seal.
- Another common one is sucking up something which causes significant damage. That can also cause the seal to fail if the damage was significant. Some replace the wear ring and/or impeller along with the rubber boot there and call it a day thinking everything is good. It won't be obvious until you go into the water next time.

In all three cases, you'll need to replace the carbon seal and possibly align the drive shaft/engine if #1 was the culprit. I've never had to do this, it's all doable if you're mechanically inclined. There are videos on YouTube on how to do all of this. If you need to align, then you need that jig (some have done DIY versions, if you're new to this, I wouldn't recommend the DIY method).

If this is above your "pay grade", time to go to someone familiar with Rotax engines and pay them to do it.

 

[Luc Lafreniere]

Also, check your personal messages. I'm sending you some more info to help guide you.

 

[SandMan123]

Thanks Luc - I’m attaching a picture of where the water was entering the engine bay. It’s just behind the bilge pump. I talked with the service manager who discovered this boat had the driveshaft replaced by the previous owner 2 years ago. We don’t know who did the work but suspect it wasn’t aligned properly and failed again. Is it crazy for a driveshaft to fail under 30 hours? The boat currently has 32 hours.

 

[Luc Lafreniere]

I don't have your boat model, but that port looks like a drain to bring water from the boat somewhere into the bilge so the pump can pump it out. That hole seems close to the center line of the boat. If you dump water in the ski locker so that it drains through the hole there, does it come out of this hole?

Where is the drive shaft in context to this?

Failed drive shafts do happen from time to time, but definitely not common at 30h unless someone sucked up something hard! I do remember one person have a stripped drive shaft teeth that is supposed to go into the impeller. But again, not common.

Yeah, whoever does the alignment work must do it correctly. It's paramount. When done correctly, it works very well. I'm at over 240h on my boat, not a single leak.

 

[Cambo]

The water level inside the bilge stabilized somehow, or stopped coming in, and it never got high enough to run the bilge pump.

Water was gushing in through the small port next to the drive shaft

Im trying to understand how water was gushing but not high enough for the bilge pump to come on

 

[SandMan123]

So that hole faces the rear of the boat, away from the ski locker but I can see how the ski locker might empty into it, since the engine bay is lower? Most of the water was in the ski locker, and seemed to originate there. Would a failed driveshaft put water into the ski locker?

 

[SandMan123]

I think some water came into that port to equalize but never got very high to cause the bilge to come on

 

[Luc Lafreniere]

The ski locker is actually lower. Water goes out to the bilge when you accelerate where it's pumped out. Yes, water from the bilge will go into the ski locker and slosh forward there and back again in the bilge until it equalizes.

Unless you cracked the hull open, that's not the source of the water.

It's definitely either the carbon seal or an exhaust hose. Since you didn't mention anything about hoses (usually obvious), but did find out about past drive shaft issues, it's almost guaranteed it's the carbon seal.

So that port is a red herring. Ignore that.

 

[SandMan123]

Ok thanks - would the drive shaft failing again cause water to come in? I’m hoping it’s the carbon seal vs the driveshaft. I did hear something pop, like a muffled pop, before we lost thrust completely.

 

[Luc Lafreniere]

Depends on what you mean by failing. If the drive shaft is rubbing excessively against the carbon ring on one particular spot due to alignment issues, then yes, it will fail again. The drive shaft must be properly aligned with the right tools. But an alignment issue isn't a failed drive shaft.

As for the pop... that will require more investigation to pinpoint.

 

[SandMan123]

Just to provide an update, the boat has been at the dealer for a few weeks waiting for them to replace the driveshaft, which had stripped. The driveshaft was already replaced once at 25 hours, and now aligned correctly. Now replacing it again at 31 hours.

 

[Luc Lafreniere]

Well then, I wasn't too far off base. Your sentence is odd, are you saying that it is being aligned correctly now that they are replacing the drive shaft again? In other words, at 25h, the drive shaft was replaced but the engine wasn't aligned correctly. But now at 31h, replacement shaft and this time, it's being aligned?

Because if it was aligned correctly at 25h and it still stripped, that's definitely odd unless you somehow jammed the impeller with a rock badly or something of the sort.

 

[SandMan123]

I really am not sure - I just bought the boat at 30 hours and the driveshaft stripped on day 2. Probably was almost stripped when I bought it. I was told by the service manager that he saw a parts order for a new driveshaft about a year ago when the boat had hours in the 20s so that’s all presumptive I guess.

 

[Luc Lafreniere]

Hopefully they get this resolved relatively quickly and you can be on the water soon! Thanks for confirming what happened. This helps others when they search the forum.

 

[SandMan123]

So..I’m being told by the Service Manager that, in order to align the driveshaft correctly, the motor needs to be moved aft. But they said there is only a sideways adjustment, so they are stumped and can’t fix it. Does anyone know how the motor can be adjusted aft since apparently there are no tracks that slide that direction??

 

[Lpennington]

Sorry you're dealing with this issue on your new boat. Outside of the surging issue the previous owner mentioned, did she mention this repair?

 

[SandMan123]

So I found out the driveshaft was replaced around 20 hours, and it stripped again on my second day out, at 31 hours. The dealer doesn’t know how to fix it because they are saying it can’t be aligned unless the motor is moved aft. I’m really frustrated.

 

[SandMan123]

And Scarab is basically saying out of warranty too bad

 

[Lpennington]

I would think whoever replaced the driveshaft at 20 hours would perform the labor at a reduced charge if not for free.