Perfect impeller/wear ring clearance ?

[ma11er]

Hey guys i just had my two impeller refurbished by impros and bought a set of SBT pump housing with plastic wear ring and i'm having problem with the plastic liner being too tight with the impeller, so i did call SBT and they said to sand the inside of the ring to have more clearance and even it's tight that the impeller will wear the inside of the wear ring since it's plastic vs stainless .. that's what i did with tons of WD40 and guess what after a few engine turns i realized that the wear ring was seized on the impeller and turning into the housing... not good

So now i'd like to know what would be the perfect clearance with impeller and wear ring? I'll bring the housings/wear rings to my friend's machinist shop and remove what it needs

I was thinking of 0.008in between liner/impeller

 

[Brandon_SC]

.008” is pretty tight.
My pumps on my 2008 are .023” to .03”
The service manual for your boat will give a min to max range of tolerance.

 

[swatski]

Hey guys i just had my two impeller refurbished by impros and bought a set of SBT pump housing with plastic wear ring and i'm having problem with the plastic liner being too tight with the impeller, so i did call SBT and they said to sand the inside of the ring to have more clearance and even it's tight that the impeller will wear the inside of the wear ring since it's plastic vs stainless .. that's what i did with tons of WD40 and guess what after a few engine turns i realized that the wear ring was seized on the impeller and turning into the housing... not good

So now i'd like to know what would be the perfect clearance with impeller and wear ring? I'll bring the housings/wear rings to my friend's machinist shop and remove what it needs

I was thinking of 0.008in between liner/impeller

That's strange... I have used those plastic/Delrin inserts with the special wear ring in the past and it was really difficult to get them in and out I had to actually put them in the freezer to fit them in and then put some pressure on them, cut them with a chisel to get them out, there's no way they could spion inside the ring.

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[ma11er]

.008” is pretty tight.
My pumps on my 2008 are .023” to .03”
The service manual for your boat will give a min to max range of tolerance.

i also have a 2008 ar210.. so 0.023 would be the minimum between liner and impeller?

Can’t find the official spec from yam

 

[ma11er]

That's strange... I have used those plastic/Delrin inserts with the special wear ring in the past and it was really difficult to get them in and out I had to actually put them in the freezer to fit them in and then put some pressure on them, cut them with a chisel to get them out, there's no way they could spion inside the ring.

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After the first liner spun into the housing i took the spare one i bought in case of a rock or sand damage during the summer.. and it was not hard at all to insert it in place.. it was almost slide fit..

 

[swatski]

After the first liner spun into the housing i took the spare one i bought in case of a rock or sand damage during the summer.. and it was not hard at all to insert it in place.. it was almost slide fit..

That's not right, I think. Hopefully @Cobra Jet Steering LLC will chime in, he uses those and he would know best.
Mine were super tight. ANd yes, the plastic rings can have very tight tolerances, that's the idea - the impeller creates its own groove.
The BRP pumps use those.

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[Cobra Jet Steering LLC]

I heard some people have had issues with aftermarket plastic liners spinning, I press my liners in with a setup I made . I would not trust a loose one. Since you had your impeller re done it may have been the reason it was so tight I am still running the original impellers with 800 hours on them. working perfectly no issues with the plastic either, ask if you can return them as defective, or use some epoxy to secure the loose one to the housing, something is definitely not making sense.

 

[ma11er]

I heard some people have had issues with aftermarket plastic liners spinning, I press my liners in with a setup I made . I would not trust a loose one. Since you had your impeller re done it may have been the reason it was so tight I am still running the original impellers with 800 hours on them. working perfectly no issues with the plastic either, ask if you can return them as defective, or use some epoxy to secure the loose one to the housing, something is definitely not making sense.

Thanks for the info.. i just bought epoxy to glue the liner to the housing just like you said, and i think ill cut a few thousandth just to be sure the impeller don’t bite into the liner again

Thanks for the info guys i’ll give updates this week end

 

[Brandon_SC]

 

[BrentEB]

Just to add another point, I bought a "new" yamaha plastic lined ring back in Sept as the stainless were no longer available. It went on with no problems and runs fine. Actually it's quieter than the other one.

 

[Cobra Jet Steering LLC]

Yes the noise you hear with the boat running out of the water is the impeller hitting the liner and if the high spots grow while the boat sits for a length of time those can even lock up the drive train and cause harm to the starter when you start it for the first time, I have seen it drag so much that I had to tell the person to spray wd 40 in the pump so he could get it started, the look I got was almost as good as the one I got when it actually worked

 

[ma11er]

Thanks for the info guys,

I just did the test, I did remove some material with stone lapping inside the plastic liner till i can easily rotate the impeller by hand, after i mounted the pump back on the boat and it did shave some more material and it was not gripping onto the liner.. but after i removed the pump i saw that the impeller was just a bit seized onto the liner and epoxy was starting to fail.. FML

Not good day, 500$ of housing that i want to throw in garbage but at the end i still need housing