I have a 180 challenger 255 hp just got it. .. I couldn't give it more than about 40% throttle or feather it ... it would top speed around 43mph with 6 people in it.so I PM the boat...the pump housing looks new the blade looks good no bends, the ware ring was wore down pretty good so I replaced it...the impellor boot had a tear in it and it was out of shape a little bit but it was still tight on the impellor so I did not replace it I thought it just kept debris out of the splines of the impellor.... I put it in the water sat. with 5 people on it ... cavitation was the same ...top speed was the same.. had to feather it a lot to be able to get it up top and out of the hole...over all it run good short of feathering it ...I run it for 3 hours then I pulled it up to the beach and sat there for an hour or so and the tide went out.... I was on bottom and when I cranked it and put it in reverse I sucked clean sand up for a couple seconds....when I got out of there I gave it gas to go started feathering it and could not get over 13 mph it would not get on top it was slipping real bad like a slipping clutch in a car... I thought I sucked something up in the pump that was blocking it so I got out went for a swim n put my hand all in it and there was nothing in it .. I was 3 miles from the boat launch I would run it to just on the verge of slipping by feathering it... then I left the throttle in one position where it would slip for a sec then grab...when it would grab the motor would get quiet and the boat would go faster but then it would slip again... I put it on the trailer, there was nothing in the pump everything looks good in the pump...so I pulled the pump off my wear ring you can barely see light between it and the blades it is much better than the old one I pulled off just a couple days ago (about the thickness of a credit card or less between the blade and ware ring) the boot for the impeller was just flopping and now will not stay on the impeller and is now even more out of shape, it is not doing it's job at all.is this my problem? when this boot goes bad can it suck air from the outer shafts? where the shafts mount to the motor is there something where it could slip? ANY help will be GREATLY appreciated....Thank you