Replacing impeller boot

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Hello all,

I'm thinking of replacing the impeller boot myself. Can anyone give me a hand with the process? I believe I have to remove the entire pump assembly from the back of the boat to access this part. Is there any tips I should be aware of before starting this? Also, should I address anything else while I'm in there?

Thanks in advance!
You need to remove the pump to access the boot. When removing the pump, remove the cone and check the condition of the bearing or it need more grease.
Once all the bolts were removed, the pump will easily come out. Just watch you don't loose the o-rings if your model has one!
If you haven't done so already, I would download a copy of the shop manual for your boat. It will help you tremendously with maintenance items such as this, especially if you are new to working on them. You can download a copy of the manual from this site (click manuals above) or you may also be able to find them elsewhere in the internet.

I saw your previous post and since you will be taking the pump and everything out to replace the impeller boot I would also take a close look at your wear ring and impeller. Also take a good look at your driveshaft carbon ring seal. I say this because I don't think the impeller boot alone would cause your cavitation problems. I suspect you may also need a new wear ring and maybe carbon seal/rubber bellows since it seems you are having severe cavitation issues. When you get everything apart post some good pictues of your pump and wear ring and we can probably tell you if anything needs replacing.

Repose to your last question: The jet pump assembly should pull right off the impeller if it is well greased and not seized up. There is no mechanical coupling between the driveshaft and the impeller, just a splined fitting. The impeller boot is supposed to keep water out of there and keep the grease in so that it will not corrode and seize up.
Hi Mike, it seems like your impeller boot is missing but I kind of agree with others this isn't likely to degrade performance to the degree you described.

It also seems you have a new or rebuilt replacement impeller recently, I can see the numbers written on it in marker. This probably means you've been experiencing some pump issues recently and had some work done already. We don't know those details but I wonder if some shop did this work for you, maybe that experience didn't go as well as anticipated?

Anyway, it's not difficult at all to replace the impeller boot, clean the contaminated grease from the hub it might have abrasive sand in the spline grease and should be filled with clean waterproof grease, the boot will help to keep the grease in and sand/dirt out of the grease.

Another piece that could be causing impeller cavitation/ventilation issues might be the carbon driveshaft seal, to replace that you must first unlock the drive shaft before removing the jet pump. unlocking the carbon seal retaining ring will allow you to remove the drive shaft after removing the jet pump.

Ans, the entire system needs to be checked, including the impeller torque on the impeller shaft, b/c it's common if the impeller wasn't properly torqued this could shove the drive shaft up into the engine crankshaft and damage the engine severely.

So if you intend on doing this work yourself, you MUST follow the factory service manual instructions exactly, to avoid making expensive mistakes!!! I think you can do this work and might need to buy some small simple tools but if the sequence isn't done according to the factory procedure I'm afraid if some important step is skipped you may suffer some expensive damage.

PLEASE download the factory service manual for 4-tec before diving in, read through the entire procedure for replacing the impeller and carbon drive shaft seal, and I think you should reverse whatever work was recently done. Unless the work was done by someone who knew what they were doing. Serious engine damage could result and it's $$$$ expensive to replace an engine.
Thanks for the reply. I asked the local seadoo shop what they would charge to replace the boot and check the carbon seal, cone etc (everything you guys have suggested they look at) since I don't have all the specific grease/oil or tools needed to to the work the right way I'll most likely have the shop do the work. I purchased the boat this spring with 30hrs on the clock and didn't think to check the impeller but it does appear to be new as there's no chips in the blades and the wear ring is clean. The previous owner was a younger person who's well-off father bought the boat and the extended warranty on. Maybe they abused the boat enough to need a new impeller. Who knows as the guy I bought it from was selling it for the original owner who paid cash blah blah. Thanks a lot for the information and for replying to my post. I've had a I/O bow rider before but this is my first foray into jet boats.
Okay then, that makes sense. So in this case also make sure the cooling system of the exhaust is flushed free of sand and cooling water can flow properly. Just to be sure in case the kids were whooping it up on a sand bar or something there might be sand plugging the exhaust manifold log or intercooler (intercooler=supercharged models).
So I tackled the impeller boot today. There was a large chunk of it just past the impeller in the jet pump housing. After taking off the F/R gate and the jet pump, I filled the cone with new grease and also put new grease into the impeller boot as per the seadoo manual. I used thread sealer on the rubber boot and replaced all the screws with loctite. Once everything was greased and tightened down I hooked up the hose and started the engine. Everything went well and sounded like it should.

Thanks for all the tips. I really just needed a #5-#6 Allen key, 1/2 wrench, wrench and 11/16 extended socket and some loctite. I hope to bring it to the lake tomorrow.

One final question on this; when hooked up to the hose the revs shot up pretty quick while I advanced the throttle. Is this normal due to using a hose vs being submerged in water? Nothing sounded odd and there was no smoke or anything, just got up to 8100 quick.


Thanks again guys!
Good job! :)

Seems like if the piece of collar was stuck inside the pump vanes, this would block water flow. So this likely caused the performance issue you described.

I think it's very easy to over-rev when the pump is out of water it takes a very small amount of throttle so this seems normal.
So we got the challenger in the water this afternoon and after a slow start (I was being cautious since it was my first repair on a jet boat) I eased up the throttle and it purred like a kitten!! Idle volume was down and overall the performance was much smoother and there was no hesitation.

I'll likely have about 40-45hrs on the clock by the end of this summer. Any recommended service or things to check in the off-season? Now that I feel more comfortable taking the jet pump apart, should I check/change/add oil and check all the seals/gaskets again after the season? I plan on having it professionally winterized, but want to get a head start on what I can do myself before putting it away for the snow.

Any tips or service thoughts?
Congrats on your first successful repair. It's a great feeling - enjoy it. Wouldn't hurt to pull the pump at the end of the season and check your work. Then follow the winterization checklist in the manual. Definitely change the oil at the end of the season. If here is any moisture in the oil, you don't want your engine internals sitting in it for months.

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