With the boat in the water it runs and goes real smooth at idle. When I get just above idle it has a loud noise. It doesn't appear to be missing. When I move the throttle up from that one spot where it is noisy, It runs great with no noise to wide open throttle. When I contacted a couple places on this issue of course they have no time to work on it. They both asked if it has a stainless prop, which it does not. Why did they ask this? Thanks. 2010 Larson 1700 115 HP.