Help, new SX190 owner and first time out notice a bad rattle in impeller

[tjkober]

All I need your assistance identifying the likely cause of this rattle please. I only notice it at certain low rpms (first time out with it today). When I got home to flush it I took the video of the rattle, I suspect this isn't normal behavior but don't have any experience to know for sure. If you will be so kind please have a listen and let me know what you think the next step should be. I'm concerned there might be a bearing or something going bad? New to jet boats so not sure how the impeller is configured yet. Thanks!



https://1drv.ms/v/s!Asiunofzy0Vvhm2FvYxwsamfSwVl

 

[tdonoughue]

Didn't look at the video, but you very likely have something stuck in your impeller. Pull the plugs and fish around in there. Probably a twig or bottle cap wrapped around something. Or a piece of a bag. If you get no luck there, check underneath while it is out of the water. 9/10 times when this happens, it is crap picked up from the lake.

 

[tjkober]

Thanks, I did check the clean out and found about 10 ft of fishing line wrapped around the shaft. I removed it by taking off the access grate on the bottom and retested but it's still making a growling noise like in the video.

Any next step guidance is much,appreciated!

 

[tdonoughue]

Ok, good. So you have basically just confirmed that it is nothing mechanical and is likely 'goop' related. That is good.

So, the thing about fishing line is that a) it is very hard to get it all, and b) the more you get, the more likely you are to blow out the rest.

Best next steps (after you make sure you got that little bit that wandered up to the forward/aft side of the impeller) is (really) to put it all together and go run it. WOT for 30 seconds probably clears out the rest and when you go back to low RPM odds are you will be fine. It sound silly and irresponsible, but that is really the way it works. Can't tell you how many times I have gotten the rattle and been convinced my boat is exploding. Stopped and cleaned things out. This board taught me often you just go to WOT and in 15-30 seconds, it is all washed away and fine.

 

[tjkober]

I just had to investigate further so I removed the impeller. No rattle at all with it removed of course. I looks decent outside of a few dings as for example in the picture. Would these cause vibration?

The spines on the shaft look fine.

What is this lower rectangle? Any reason to open it up and investigate?

 

[tdonoughue]

Nah. I think I have dings in my hull bigger than that. Certainly in my impeller. Bet you clean it up and put it together and get no vibe.

 

[tjkober]

So I took the impeller shaft off entirely and of course no vibration.
Impeller is nicked a little but nothing major, splines look good, shaft looks pretty good (slight wear just below the splines).
I put only the Impeller shaft assembly back on and the noise/vibration returns.

Can a guru please have a look at my two video links and give me an opinion?

From outside by the exhaust https://1drv.ms/v/s!Asiunofzy0VvhmyOwPJCuySa4pIr

From inside engine compartment https://1drv.ms/v/s!Asiunofzy0Vvhm6HVVoySCKm3cVs

If I had to guess it sounds like a harmonic balance issue but I'm baffled why it would be so extreme by looking at the impeller. My other concerns is could it be the housing bearing on the inside? I just bought the boat a few days ago and pumped 15 shots of marine grease in it (no idea if that's enough as I see they provide recommendations by weight) but that obviously didn't help. Do these sometimes go bad at 140 hrs?

Thanks for your help!

 

[Cobra Jet Steering LLC]

Look at the pump liner if you see dark spots you probably have dissimilar metal corrosion under the liner causing it to have high spots and those are making contact with the impeller, very common especially after a boat sits for a long time. It can get bad enough that the engine will drag when first starting it or even lock up on really bad cases.

 

[tdonoughue]

Yes, I would be very surprised if the bearing is bad. If that were bad, it would be rattling even with the impeller removed. Check the pump liner as Jeff suggests.

 

[Gym]

Hi @tjkober and welcome to the forum. I'm guessing, whereas your boat is a 2013 you bought it used. Is this the first time out? It's important to note that these boats are generally louder out of the water and can make a rattling noise. That being said if they rattle too much it could be the impeller coming in contact with the liner as Jeff stated. He also suggested looking for dark spots on the liner where the impeller might be contacting the liner. You should also run your fingers over the edges of the impeller to see if any of the edges are slightly rolled over indicating liner contact. You can also remove the entire pump & impeller assembly, slowly turn the impeller shaft by hand to see if there is any contact. You can do the same with the pump installed by removing the spark plugs from the motor to eliminate the compression. The gouge I see in your pic is not causing your problem and is from a foreign object. You can carefully file off that burr with a fine file. Let us know how you make out.

 

[Scottintexas]

What is this lower rectangle? Any reason to open it up and investigate?

That is the strainer for your cooling water to go to your engine, it's not the problem,

You're way overthinking it with the harmonic balancer talk,

If it was me I'd put it back together and go test it on the water, it's always going to be noisy and gravely on the hose, if you've already found fishing line there was probably more and it's already gone,

 

[Scottintexas]

and be sure to check out the FAQ tab at the top of the page for lots of great tips, especially watch the video about "how your cooling water flows"

 

[swatski]

So I took the impeller shaft off entirely and of course no vibration.
Impeller is nicked a little but nothing major, splines look good, shaft looks pretty good (slight wear just below the splines).
I put only the Impeller shaft assembly back on and the noise/vibration returns.

Can a guru please have a look at my two video links and give me an opinion?

From outside by the exhaust https://1drv.ms/v/s!Asiunofzy0VvhmyOwPJCuySa4pIr

From inside engine compartment https://1drv.ms/v/s!Asiunofzy0Vvhm6HVVoySCKm3cVs

If I had to guess it sounds like a harmonic balance issue but I'm baffled why it would be so extreme by looking at the impeller. My other concerns is could it be the housing bearing on the inside? I just bought the boat a few days ago and pumped 15 shots of marine grease in it (no idea if that's enough as I see they provide recommendations by weight) but that obviously didn't help. Do these sometimes go bad at 140 hrs?

Thanks for your help!

The bearing you pumped grease into is the intermediate bearing (and you pumped it into the casing of the bearing, the bearing is sealed) - no worries there.
If you have the pump out, you may want to check the pump bearing - just take the cone off. Save the o-ring. Look for any sign of water ingress, if none, and the bearing moves smoothly - no worries (most likely scenario).

If you are in salt, you most likely have wear ring SS insert (non-replaceable) swelling, as @Cobra Jet Steering LLC pointed out.

BTW - thanks for posting those clips, very useful. I would say, you likely have some impact points (impeller rubbing on the swollen spots in the wear ring) - nothing to worry about as long as the impeller is moving, it will just be a bit louder.

As @Gym pointed out, these boats are STUPID loud, and the engines sound like there are loose marbles inside - normal, lol.

Really, your boat is most probably completely fine, you just may need a new wear ring.

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[buckbuck]

I watched your videos and didn't hear anything unusual. That is the way they sound while on the hose.

 

[tjkober]

Thanks everyone, I shined a flashlight inside the bearing housing and the plot thickens. Found what appears to be a bearing seal and was able to pull it out. I guess now the move it to pull the inside bearing housing?

 

[swatski]

Thanks everyone, I shined a flashlight inside the bearing housing and the plot thickens. Found what appears to be a bearing seal and was able to pull it out. I guess now the move it to pull the inside bearing housing?

Looks like you blew the seal. I would not worry about this, unless you have water coming it. Changing this bearing assembly requires moving the engine.
Here are some links on this, please look at the links in @Cobra Jet Steering LLC posts.
https://jetboaters.net/threads/intermediate-bearing-repalcement.16663/

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[Cobra Jet Steering LLC]

Most likely the rattle and ringing you hear is the pump liner and the impeller making contact.
The intermediate bearing usually does not make noise when it goes bad .
My first hand experience says someone over greased it and blew out that seal.
My experience has also shown me how to avoid doing that. I currently have close to 600 hours on both of my bearings with no problem yet with either one. I have posted pictures of failed bearings that I owned that were way worse than this one and leaking water like crazy but they never made any noticeable noise.
If it's your liner causing the ringing as I suspect it is, the fastest and easiest way to check is to spray some white lithium grease " preferable" in the pump or some wd40 etc and start the engine if the noise is less obvious after spraying this in the pump you have located the culprit.
However you now must replace the bearing and possibly the rubber vibration dampener while you are at it and the pump liner section.
Hopefully you can clean up the impeller, none of this is going to be any fun. My advice! Do some research on this web site and others ,follow only reliable and credible advice as there is always a lot of questionable info available on the internet.

 

[tjkober]

Thanks again for the feedback. I checked the inside of the impeller housing and there are some fine scratches in it, not deep nor do I see wear on the edges of the impeller blades but as you elude it wouldn't take much contact at rpm's to make some disturbing noises. I lightly greased the inside of the housing but didn't get a chance to fire it up to see if it was quieter with a grease buffer.

So more than likely the next step is to pull the inside bearing assembly which requires unbolting the engine and loosening the exhaust clamps so I can pull it forward enough to remove it?

If I confirm it is indeed bad (which is almost surely the case) did someone mention you buy the entire assembly as a unit and swap the whole thing out?
Or is it best it break it down and swap out only the defective pieces? If piecing it out looks like I may need to replace parts 3,5,7,8,9 (assuming circlips are still good)?
Does the impeller housing look like it would need to be replaced?

Sorry I'm not tracking what the rubber vibration dampener is, is that inside the bearing assembly?

Thanks again!

 

[Cobra Jet Steering LLC]

The dampener is between the teeth of the rear flywheel for a lack of a better term and the shaft that goes into the bearing housing the rubber cushions the contact between the two parts.. As for the wear ring issue it is common. To resolve the issue you may want to go to a totally stainless section and eliminate the problem from happening again, Or just replace the section and wait for it to reoccur . I do something different but I will leave that out of the conversation since I was informed this is not a good option for boats.
the rubber dampener I mentioned looks like this

is located between these one goes on the shaft that is in the intermediate bearing shown here

I ran across the picture of my totally destroyed intermediate bearing while searching for pictures of the parts, The only way I knew it hatched was it nearly sank me.

 

[Dan_NC]

I previously had an AR192, she sounded the same way when I would flush the engine. I doubt you have any serious issues. Welcome to the forum and enjoy your new boat!