new impeller dragging?

[41magnum]

recently replaced the impeller in a 30 yr old 35 Merc and it does not spin freely,,,,,,,has a little drag.
Does that drag mean it is sealing properly?
Should it spin freely?

When running in water/pond the motor pee's good up to about 3/4 throttle BUT, any higher, THEN it spits and sputters and water flow is interrupted and reduced. NOTE we did knock out a bunch of mud dobber nests during the clean up.

 

[racerone]

It takes a surprising amount of effort to turn a water pump.

 

[Mark ofs]

For what its worth...my '85 - 35hp Mercury does not loose flow on the tattletale at WOT. I rebuilt waterpump/impeller with Merc kit in 2018