Removing Impellers in 10GS

I have a 1 HP pump and motor 10GS. This is way to much head. How do I remove the impellers to reduce the pump head? I need to remove 4 impellers.

Thanks,
NormanWell

Unscrew the pump head, slide the impeller stack out, remove the snap ring, slide impellers off. The problem is you need a spacer to put back in place of the removed impellers so the snap ring can hold everything in place. I just grind the impeller down and leave the part that slides over the shaft as a spacer.

Or you can install a CSV and it will reduce the head for you.