Impeller noise!

[Epp'ic]

Good day fellow Jetboaters! I have a 2021 AR250, I sucked a hat into the starboard side intake. Impeller was stuck and would not move, I removed the impeller and got out what was left of the hat. Once cleared the impeller spun freely with no issues, did not seem to make contact with the sleeve. Put it all back together and when idling in the water that impeller is noticeably louder than the port side. When I accelerate the noise goes away and the boat runs smooth. Should I replace the impeller?

 

[Scottintexas]

when you sucked the hat up did the engine shut down by itself ??

if so maybe you now have some play in the splines at the end of the shaft ?

You could take the impeller off and measure the blades to see if they are equal pitch or if edge is smooth but the whole pitch got bent ??

maybe measure the gap between the impeller and the wear ring,

the real question is "noticeably louder" to loud and a distraction, do you hear it or do your guest look over and say "what's that noise?"

 

[Epp'ic]

Thanks for the reply! The engine did not shut down by itself. It is loud enough people might notice, but not so loud they would say "what is that noise". When I removed the assembly, I looked at the splines and did not see any damage or metal shavings. I also used a borescope to look in where it goes and did not see any damage there either.

 

[Scottintexas]

I sucked up a rope one time, so tight it forced the engine to stop itself, others have had the same thing happen without further consequence,

did the hat have any metal on it ? with metal I really have a hard time believing you bent something,

my first guess would be you threw something out of balance at the intermediate bearing and that's causing the wiggle at idle,
but I would start with easy stuff first, measure the impeller gap,
maybe run the engine on the hose with the shaft out to see if it sounds different ?
I think it's going to require a lot of troubleshooting,

an extra set of impellers is not a bad thing for a jet boater to have on hand so maybe it's worth it to buy a new set and just have a good spare to save a holiday trip, ( impeller shafts were crazy expensive that last time I heard )

 

[Epp'ic]

Thanks again. The hat did have a small metal pin attached that was caught in the impeller gap. I'll try your suggestion when I get a chance, the boat is stored about 4 hours away at Lake Havasu.

 

[anmut]

Here's the question - was the noise always there and you're just hyper aware of it, or is it new? My 2020 impellers make a rattling sound at idle and have since the day I brought it home. No issues with functionality and, similar to your experience, the slightest increase in rpm (no wake mode 1) and the sound goes away.

 

[Epp'ic]

That is a possibility, but one is definitely louder than the other. Sitting still in the water, I ran one engine at a time and the port was basically silent, the starboard was not. I just want to make sure I am not causing more damage by continuing to operate it.

 

[Epp'ic]

I sucked up a rope one time, so tight it forced the engine to stop itself, others have had the same thing happen without further consequence,

did the hat have any metal on it ? with metal I really have a hard time believing you bent something,

my first guess would be you threw something out of balance at the intermediate bearing and that's causing the wiggle at idle,
but I would start with easy stuff first, measure the impeller gap,
maybe run the engine on the hose with the shaft out to see if it sounds different ?
I think it's going to require a lot of troubleshooting,

an extra set of impellers is not a bad thing for a jet boater to have on hand so maybe it's worth it to buy a new set and just have a good spare to save a holiday trip, ( impeller shafts were crazy expensive that last time I heard )

I checked, the impeller shaft is $326 and the impeller is $164.

 

[anmut]

That is a possibility, but one is definitely louder than the other. Sitting still in the water, I ran one engine at a time and the port was basically silent, the starboard was not. I just want to make sure I am not causing more damage by continuing to operate it.

I would just go out and run it. If you have an issue with your pump or impeller, it won't hide behind a nice full throttle send.

 

[Epp'ic]

When I test drove it last weekend, I was able to easily get it to 45 MPH (just the wife and I and no gear) with no issues. Everything was as smooth as can be. Am I at the risk of damaging something else? I only ask because we store the boat 4 hours away at the lake and I don't plan on going up there again until 30 June for the weekend.

 

[Epp'ic]

Picture of the hat! At least what I could not get out until I removed the assembly.

 

[Scottintexas]

I wouldn't think you'd do any further damage,
We've had people suck up ropes, golf balls, CHUNKS of wood and some of those are so tight they actually cause the engine to stall with no ill effect.

you didn't experience that, so causing additional damage is really hard to imagine, like you'd be the first one in my 15 years of following yamaha jet boats

 

[Epp'ic]

Thanks for the replies. I appreciate the assistance.