I have a 24' boat with a 250 Yamaha and occasionally when docking, if I have to give the throttle a little burst in reverse, the engine makes a loud "shuddering" noise. I think it is actually lifting out of the water, or at least trying to, and the noise is when it comes back down against the boat. I'm always looking forward, so don't know what is actually happening. Is this normal ? I've looked at the mounting and everything seems good. Nothing loose or broken or missing.
