four winns fling getting hot and no power

[dodgeowner02]

i bought a 94 four winns fling and the previous owner said it ran great 3 yrs ago when he stored it i put it on the water and the boat ran about 4 mph at full rpms and was getting hot
is this an impeller issue or is something else i would like to get on the water if its the impeller where can i find one i hear they dont make them anymore and do they really run around 600 dollars