Mercury 4 stroke 75 hp 2007

Hello everyone, about a month ago changed all fluids and impeller after noticing water wasn't pumping out piss hole and it was alarming out, got it all done same, thing not pissing, I'm using hose in driveway. Took apart replaced impeller, put new one in same way. Took it apart again, double check everything looks good, same thing happening with hose, then i take it to boat ramp it's pissing out hole where the hose goes and not the piss hole. Took back apart because a few people thought it was in backwards, impeller looked like all was good so now I'm a little confused as whas going on, also put about 20 inchs of weed wacker cord up it, any help would be appreciated. It's a 2007 mercury 4 stroke 75 hp. Forgot to mention it's blowing a little air out of piss hole. Pic on pallet is new impeller, pic with gasket is the one I replaced. Thanks Dave