3rd Summer - 1st real issue

[andrei_b]

Hi Guys,

We've been enjoying our 2014 Scarab 195 HO Impulse for the last couple of years now, with just regular maintenance and no issues until the other day.

We had just left the dock and were idling out of the loading/unloading "no wake" zone, and no sooner did we get past that which is when I throttled up and within 1-2 seconds, I felt something letting go down in the hull of the boat. All manner of vibrations and rattling even at part throttle, so I turned right back around to head back in under idle power essentially.

We pulled the boat out of the water and the first thing I checked was the intake grate, which looked clear. I couldn't see anything stuck or blocking the impeller, so I went around the back to the jet pump discharge cone, where I could see some grasses stuck between the impeller and the nose cone area. Not being able to pull it out, we trailered it home.

Today, I was able to remove the reverse bucket and the jet pump discharge end. To my surprise, the impeller remained stuck onto the driveshaft. The grasses that were previously stuck now simply fell out, but I couldn't pry off the impeller from the drive shaft to save my life. It has maybe 1/2 in play to where I can pull it towards me, but that's it. It seems stuck on the spindles of the driveshaft.

Again, I was very surprised to see that the jet pump discharge nozzle had come loose from the impeller. The helpful video that @Luc Lafreniere had posted on removing the jet pump showed the impeller simply sliding off with the jet pump discharge end. It seems the jet cone end that threads into the impeller unthreaded itself, which then allowed the impeller to bounce around inside the housing, scratching up the wear ring and making horrible vibrations when I even touched the throttle.

Now my dillema: I'm unable to slide the impeller off the driveshaft spindles. It's likely with all the bouncing around in there, those spindles got damaged and now the impeller is stuck. I can also feel some side to side and up and down play on the driveshaft, not sure how much (if any) is allowed. Since this is as far as I got, I'm thinking I may end up having to replace the driveshaft (with the stuck impeller on it), and replace the jet pump components (impeller, wear ring, housing).

How difficult is it to replace a driveshaft on these BRP Rotax engines? Is this something anyone has tackled before and if so, can you point me to a how-to video? I snapped a few pics to show you where I'm at and the condition of the jet pump housing:




The scratches in the wear ring catch your fingernail pretty good, so I think it would be a good idea to just replace the entire housing with all new parts; the problem remains getting the old impeller off, which likely will require me removing (and maybe replacing) the driveshaft itself. I did remove the nose cone itself and everything in there looks perfectly good, all the grease is in there, no water or other contaminants. I just forgot to snap a pic. Also, that blue stuff on the threads is threadlocker, which I put on thinking I'd be able to just reattach the housing to the impeller, but no luck. The threads on the housing and also on the impeller may have gotten damaged while they were disconnected and the impeller was just bouncing around in the housing.

Would I also need to replace other parts while in there? Seals, carbon ring, etc.? What would you do? What would you advise I do? At this point, I'm as stuck as that impeller. The only other solution is to find a boat shop and have them do all this work for me.

I'd very much appreciate your thoughts, and thanks in advance.

 

[Luc Lafreniere]

Had the pump ever been maintained before or is this the first time?

- Wear ring I'd replace based on what I'm seeing. It's not horrible, but not great either.
- If you can't pull the impeller off the shaft, then yeah, you'll likely need to pull the shaft out. Maybe then you can knock some sense into that impeller without damaging it. From that side, the impeller looks in good shape.
- If you do pull the shaft, then yeah, I'd consider replacing your carbon seal at the same time. If you have no signs of carbon seal wear, you're probably fine, but you will have done most of the work already...
- Definitely make sure your pump is in good shape. Bearings, etc. Now is the time.
- Make sure you align the drive shaft with the proper alignment tool otherwise you could prematurely wear out the new carbon seal.
- Make sure to grease the splines of the drive shaft when you reinstall the pump.
- Make sure you have some fresh oil/grease in the nose cone.

All of this being said, I've never had to replace my drive shaft or carbon seal. But there are many such videos on sea-doos on the youtubes.

 

[andrei_b]

Hi Luc,

This is the 1st time I have ever pulled the pump myself to clean/inspect/etc. The dealer I purchased it from in 2024 had done all the pre-sale inspections and required maintenance for the hours it had at the time.

The driveshaft alignment tool: I'd appreciate a source for this, as well as a trusted source for the driveshaft itself. I've perused the interwebs and saw several options but not sure which one is supposed to be a direct fit.

I'm awaiting quotes from a few shops, but what would you guesstimate this might cost me if I had a shop do it vs attempting it myself?

I've seen a few YT vids and it doesn't seem too terribly complicated, but I'm not sure I want to take the chance and do something improperly.

I think I'd like to source a whole new jet pump assembly, complete with impeller, wear ring, bearings, etc. and if I'm able to swap out the driveshaft then I should be able to just slide the new assembly onto the driveshaft, bolt everything back together and we should be good, right?

EDIT: I looked up on Cecil's Marine site and found basically all of the parts I'd need to replace, starting from the driveshaft and its associated bits to the jet pump housing, impeller, etc. and parts alone would be almost $2200 No idea what labor costs are these days, but I can imagine it could easily be another $1-2K, so I'm probably looking at a $4K repair job.

Add to that, it's time for an updated "maintenance free" supercharger, as my current original one has 220hrs on it...

Difficult decisions to ensue...

 

[Luc Lafreniere]

The only official parts provider for this are Scarab dealers specifically. It's the only way to ensure you're getting the correct BRP Rotax parts for Scarab boats. Sea-Doo parts may fit, but they won't advertise it. So I suggest ordering these things directly from an approved Scarab dealer. Have your HIN ready. They should sell the alignment tool as well. But if not, I suspect those can be obtained elsewhere. But I don't know personally where.

If they did maintenance on it in 2024, it's very odd that the shaft is stuck to the impeller. This feels like either the splines are messed up and jammed or they didn't do what they claim they did and didn't grease it.

The entire pump replacement is definitely not a bad way to go. You can always sell the leftovers for parts after. That or a complete restore of the pump. If you're planning on keeping the boat, I'd definitely do it "right".

I don't know the costs... but you can see an example here: Online Store Sport Jet Boat Parts

The 250HP Scarab pump (assuming it's comptible which you need to check) is $439. But you have to add an impeller, so I'd expect about 1k USD for a new pump alone. But you can easily get quotes by calling a Scarab dealer.

 

[andrei_b]

Good ideas, thanks Luc.

I was comparing the threads on the new jet pump assembly and the threads on my current one, noticing quite a lot of what looks like corrosion. Almost as if the threads may have been loose for some time until a blockage back there finally undid the impeller off the jet pump assembly. So whether they inspected it or not (or how thorough their inspections are) I cannot really know, other than what they said.

In any case, I'll contact a Scarab dealer for more info while awaiting quotes from a few local shops that are familiar working on ski-doos and other jet powered watercraft.

 

[Luc Lafreniere]

Yeah, it's hard to determine that... let us know what the conclusion is once you decide what to do. Costs included. It's good for others to be able to find this info.

 

[andrei_b]

Welp, the shops I reached out to around me do not service jet boats, only skis and smaller PWC. The only other option is to take the boat 1-2 hrs away at a dealer and basically pay out the nose for the repairs, which I'm not inclined to do. It is an older boat, no warranty, so I'm going to tackle the work myself.

Essentially, I'm removing the driveshaft and carbon seal, replacing those items, and then will slide on a new jet pump housing assembly complete with impeller, all from Cecil Marine who have been great to deal with so far. I've ordered the carbon seal fork tool and the driveshaft plate holder tool for now, to continue disassembly.

Fun fact: to access the carbon seal and driveshaft, the supercharger also has to come out. So it looks like I'll be swapping that out with the upgraded one as well. All this for the low, low price of $3700 in new parts and $2-300 in tools, supplies. I'll need to drain the oil out first, since pulling the driveshaft opens up the low point on the engine.

I'll let you guys know how it's going and may ask questions as needed.

 

[Luc Lafreniere]

Honestly, based on what I've seen over the years, it's not a difficult job. Just time consuming. I suspect you won't have any major issues. Put some music on, have an adult beverage, make sure to have a young child with small arms that can reach for things in the engine bay (small wife is acceptable as well) and most importantly, ensure you have the right parts.

And yes, similar story here in Ottawa. Nobody wants jet boats. Takes too much space and same amount of profits as skis. Plus in many cases, they need a software licence to access Scarabs specifically (different than Sea-Doo licences). I've been doing my own maintenance for these reasons as well. I've learned to enjoy it and not worry too much if I make a mistake. Just take your time

And definitely take some photos through the process!