it should idle high out of the water only cause theres no presure on the impellaer causing your rmp to go down, take it out crank her up she should be good, idle should be around 2800-3000 rmp if im not mistaken
i thought the same thing befor i put mine in the watter turns out to be a comon miss understanding however if if seems to idle fast in the water then look more into it. it should just float around maybe 2mph at idle