hi
rvitko
thank you for your reply,
At the retailer the pump was opened and checked, the ceramic bushing with a red silicon sleeve,were fine, reassembled and checked, the pump was still the same. i believe the drive shaft is off balance.
like i said my brothers 9420 skimmer with the new pump is very quite, He did have the older first gen pump which was very nosiy, the drive shaft replaced
twice as they had broken, so replaced the new version pump.
himat