We just purchased and started using a 2009 175 Optimax Pro XS and so far it has a little bit of a disturbing trend. After running around, sometimes, not all, the engine will rev up and not idle down until we turn the motor off. As I said this is a new motor. Is this a temporary issue or should I be working with the dealer to make this go away? Really bothers the Admiral when she is loading the boat onto the trailer and it won't slow down for her. It seems that the motor idles fine when first started, but will accelerate once it has been running a while.