Impeller size

[Brice Ray]

I am trying to replace the impeller on my 1999 Ski Nautique Super Sport and when I removed the old one it was very beat up so I am trying to put the new one that was in the boat when I bought it but it barely fits in and when it does all the splines on it are completely bent over. Is this normal or is this impeller too big for this pump? Let me know if you need more info. Thanks

[MTRBTR]

That’s normal

[Neptune442]

Totally normal. I used a small amount of dish soap on the splines to help it slide in easier.

[Infinity]

Some people install a zip tie to bend the vanes to start it sliding in and then cut off the zip tie before pushing it all the way in. I just liberally put dawn dish soap on all the vanes and turn impeller as I am sliding it into the housing.
Before you do that tho if your old impeller is missing pieces, you want to make sure that there are no pieces in your cooling system, they can get trapped at trans cooler if you have them and need to be back flushed to remove or you can overheat the boat. Also, check inside of impeller housing to be sure its clean/shiny. Since older boat, housing may need to be cleaned or even lightly wetsanded with 2000 grit, the smoother/cleaner the surface the better the impeller will perform.