Is carbon ring “play” normal?

[yetisoldier]

I’m trying to fix a cavitation issue on a 1998 Sportster 150 (single engine). I can slowly feather the throttle and eventually get up to 35 mph, but if I try to accelerate “normallyI cavitate almost immediately. I’ve already replaced the wear ring and ensured the pump shoe is well sealed to the hull. Next up is the carbon ring.

The existing carbon ring had about 1/8 to 3/16 in play in it around the shaft. I tore everything apart and was about to put it back together when I noticed the new carbon ring was about the same! The part was aftermarket but listed the same OEM part number listed for my boat.
I don’t want to waste money on a different carbon ring if the play is normal.

TLDR
Is it normal for a new carbon ring to have a fair bit of play around the drive shaft? Or did I get a bad part?

I did a fair bit of searching and didn’t come up with a conclusive answer anywhere. I don’t have any friends knowledgeable in this so I turn too you! Thank you in advance!

 

[JJinSC]

Yes, play around the shaft is normal. The boot holds it so that it floats and does not really touch the shaft when running and the pump fills up with water. The important thing is that its flush against the hat shaped collar it mates against and with enough pressure.

 

[yetisoldier]

Thanks for the reply! I just finished putting it all back together with the new part! Now I just need to get out on the lake and see if it solved me cavitation issue! I pray it did!