Buying a used boat with a cavitation issue?

[Fishwater2002]

We’re in the market for a used Yamaha & there’s a SX230 listed about 3 hours away. I spoke with the owner & he was very upfront about why he was selling & what known issues the boat has. Currently the boat is still wrapped since he hasn’t had time this year those it but late last year he sucked up a piece of wood so he removed the pump assy on that side & replaced the wear ring with a plastic ring, he felt that the impeller was fine so he only replaced the wear ring. Also to note that the center bearing was replaced previously on that same side. After replacing the wear ring it he water tested the boat & got cavitation from that side, it was the end of the season so he pulled the boat, wrapped it & left it for this season. He hasn’t had time to get to it this season & is selling the boat now due to personal reasons. He fully admits that he may have missed something with the repair last season & more than likely feels that is the cause since the boat had zero cavitation prior to sucking up the wood. It sounds like an impeller to me but I’m asking for advice since I’ve never owned one of these boats before. Other than that the boat looks clean, the owner was knowledgeable about these boats & took care of it from what I can see in the pictures.

 

[Weeb]

It doesn’t take much damage to an impeller to create cavitation.

 

[Murf'n'surf]

Worst case scenario you'll need $1500 in parts. Shaft, seals, impeller if they really did some damage....but highly unlikely.

Most likely you are looking at an impeller and new wear ring/pump housing. Things to look at as well are the clean out plugs, are you able to easily remove and lock in place? Check the sealant around the pump and in the tunnel, loose or missing sealant can cause cavitation.

We are here to help if you need anything!

 

[Scottintexas]

how much is he asking for it?

worst case scenario he's lying about a whole bunch of stuff including engine problems,

we normally replace impellers, I confuses me that he chose to just replace the wear ring, that's not a normal process,

the "center bearing" do you mean the intermediate bearing that connects the shaft to the engine or a bearing in the nozzle at the impeller?

maybe if he runs the engines on the hose and they make proper rpm you can hope the only problem is the impeller,

A jetski shop can easily take care the impellers,

if you buy this boat in non working condition, realize it could be $200-300. and a week and you've got a good boat or you've got month's of troubleshooting and a boat that won't go,

I'd be very cautious,

 

[Fishwater2002]

how much is he asking for it?

worst case scenario he's lying about a whole bunch of stuff including engine problems,

we normally replace impellers, I confuses me that he chose to just replace the wear ring, that's not a normal process,

the "center bearing" do you mean the intermediate bearing that connects the shaft to the engine or a bearing in the nozzle at the impeller?

maybe if he runs the engines on the hose and they make proper rpm you can hope the only problem is the impeller,

A jetski shop can easily take care the impellers,

if you buy this boat in non working condition, realize it could be $200-300. and a week and you've got a good boat or you've got month's of troubleshooting and a boat that won't go,

I'd be very cautious,

He said the mid shaft bearing housing was replaced prior to any issues. Agreed, I was kind of surprised that he went with replacing the wear ring instead of the impeller, at the time he said that he felt that the impeller was fine but he could have missed something.

 

[adrianp89]

Take for a ride and see for your self. Cavitation might be mild and boat runs strong... and he is just being super honest.

 

[Fishwater2002]

So I bought the boat & after running it on the hose I could hear that the starboard pump was grinding while the port side was quiet. Got it home & pulled the impeller, I don’t really see anything too bad on wear ring except for a faint pock mark at about 5:00. There’s more “wear” on the inside of the wear ring closest to the transom but it doesn’t feel bad with my fingernail. The other thing I see is that the ends of the impeller are equally worn all the way around & shiny, there’s also some wear on the shaft where it slides through the hull into the intermediate bearing. How do I check the intermediate bearing?

 

[Scottintexas]

You should measure the gap between impellers and wear ring
The wear ring doesn’t look bad
The rough spots on the impeller is long term cavitation
The shiny spot on the mid shaft, is probably a rope that got sucked up
Shiny by the splines is usual wear it passes thru hull

on the picture I marked make sure you have sealant there and it’s still adhesive attached and you can’t pull it with your fingers

 

[Scottintexas]

The impeller should have a part number printed on it
What is it?

 

[Fishwater2002]

The impeller should have a part number printed on it
What is it?

6B500

You should measure the gap between impellers and wear ring
The wear ring doesn’t look bad
The rough spots on the impeller is long term cavitation
The shiny spot on the mid shaft, is probably a rope that got sucked up
Shiny by the splines is usual wear it passes thru hull

on the picture I marked make sure you have sealant there and it’s still adhesive attached and you can’t pull it with your fingers

View attachment 205759

There’s some sealant there but looks pretty old & missing in some areas. Nothing moves though when I try to grab it

I’ll take the housing off for the wear ring tomorrow to measure it, just looks like four 14mm bolts & the one 6mm correct?

 

[Fishwater2002]

I took two videos, one is the noisy starboard side & the other is the quiet port side but don’t know how to upload them here.

 

[Scottintexas]

You have to upload to YouTube then give us the link

Gravely sound is normal
I’d put some silicone on the missing spots as that could easily be the problem
Put it back together and give it a water test

 

[Fishwater2002]

Try this link for the movies

Boat noise - Google Drive

drive.google.com

 

[Murf'n'surf]

Have you inspected your cleanout plugs?

 

[Scottintexas]

Try this link for the movies

Boat noise - Google Drive

drive.google.com

if that's an apples to apples comparison they definitely have a different sound,

I wouldn't necessarily say the louder one is "bad"

I might run the engine with the impeller out just to see if you hear anything you shouldn't (like an intermediate bearing), you probably won't hear anything but just for troubleshooting curiosity,


nothing in you pictures look noticeably bad,

I don't know how the check an intermediate bearing, most of the time when an intermediate bearing goes bad it leaks while on the water,


.

 

[adrianp89]

How does it run on the water?

 

[Fishwater2002]

Have you inspected your cleanout plugs?

The guy I bought it from replaced both cleanout plugs because when he bought the boat from the original owner they were seized from lack of use. So in other words it has good semi new clean out plugs.

if that's an apples to apples comparison they definitely have a different sound,

I wouldn't necessarily say the louder one is "bad"

I might run the engine with the impeller out just to see if you hear anything you shouldn't (like an intermediate bearing), you probably won't hear anything but just for troubleshooting curiosity,


nothing in you pictures look noticeably bad,

I don't know how the check an intermediate bearing, most of the time when an intermediate bearing goes bad it leaks while on the water,


.

I was wondering if I could run it without the impeller & everything in it, guess I’ll give it shot & see what happens.

How does it run on the water?

No idea yet, I just bought it but I’m planning on dropping it in this week after I reseal the area pointed out in the thread above.

 

[Cobra Jet Steering LLC]

He said the mid shaft bearing housing was replaced prior to any issues. Agreed, I was kind of surprised that he went with replacing the wear ring instead of the impeller, at the time he said that he felt that the impeller was fine but he could have missed something.

go under the boat and look at it check the edges and the clearance from the end of the blades to the liner if it has huge space or bad blades it needs repair.

 

[Brad_Ct]

The guy I bought it from replaced both cleanout plugs because when he bought the boat from the original owner they were seized from lack of use. So in other words it has good semi new clean out plugs.



I was wondering if I could run it without the impeller & everything in it, guess I’ll give it shot & see what happens.



No idea yet, I just bought it but I’m planning on dropping it in this week after I reseal the area pointed out in the thread above.

Yes you can run the engines with the pumps removed.

 

[Cobra Jet Steering LLC]

The guy I bought it from replaced both cleanout plugs because when he bought the boat from the original owner they were seized from lack of use. So in other words it has good semi new clean out plugs.



I was wondering if I could run it without the impeller & everything in it, guess I’ll give it shot & see what happens.



No idea yet, I just bought it but I’m planning on dropping it in this week after I reseal the area pointed out in the thread above.

Add EZ locks to the plugs very inexpensive and time tested insurance against a blow out. $43.95 for a twin set do a search on BLOW OUT PLUGS