lake nehai

well i just bought a 92 kawa 750ss and it ran fairly well this weekend. i just had a couple of questions. is it supposed to idle fairly fast? and is there supposed to be a lot of smoke from the exhaust? if if there of these are a problem would you please let me know how to change it. im assuming that if it is idling to fast to just adjust the throttle cable. but please correct me if im wrong.

also i weight about 165 and if i just push the throttle all the way in it feels like the jetski kinda bogs down, it wont plain out and the engine is roaring im just not moving too fast. i have to slowly press the throttle to finally get to top speed. i visually checked the impeller and it is torn to hell, so im assuming that is the problem. if so what would be a good aftermarket impeller to get and where can i get it?

thanks in advance