Just took my boat out for the first time this year and after about two min on plane my engine made a very loud grinding/low screeching noise. I instantly shut the engine off and removed the dog house and saw that there was some smoke coming into the engine compartment from the main drive shaft in the lower unit. This tells me it is not an engine problem I believe. also I noticed the temp increased significantly but not to a dangerous level because I shut it down right away. Im thinking it is either the impeller or the gimbal bearing (just because of the noise). If anyone has any ideas or suggestions I would greatly appreciate it. Also this is on a 3.0 liter merc with an alpha one outdrive.