Saw the neighbor at the lake put their boat in, with the help of another neighbor. 17' bowrider with mercruiser. First, they launch w/o plug. 10 min or so later they figure out why there's water in the boat. Pull the boat back on the rail system to drain, then put plug in. Re-launch. Start engine for the first time of the season, mucho white smoke. Sounds really dry to me. Over the clatter, I hear "it probably just needs to run a while" at which time they put lawn chairs in boat (because seats are missing because floor is rotted from repeated launching without plug) and go for 10 or so minute high speed ride around lake. I can see smoke following them. When they get back to their dock, there is a lot of white smoke and it smells like burning plastic/rubber down wind from them. They open the doghouse at which time I was wondering which fire extinguisher to run there with. But I guess it wasn't flaming yet and they didn't seem too worried and draped some wet towels over the motor until the smoking stopped. After some head scratching, they pulled it back up onto the rails where I imagine it will sit for a long time. I heard later that the neighbor who went to help out, did so because he told them he "knows everything there is to know about boats" and would help to get them going for the season. I know him and also know he does not, nor has ever owned an I/O, so I expect he doesn't know much about them. It was the blind leading the blind. I've seen how these people operate a boat. Scary scary. After seeing too many close calls from plain stupidity, I vowed I'd never "help" them get their boat going. I don't want the guilt of a guest kid or someone else getting run over, because I'd helped them get it started when I know they are down right dangerous when operating the boat. I imagine what happened was a severe overheat, from either not closing the manifold/block drains after winterizing, or having never serviced the impeller (or both). Could be a cracked block from improper winterizing last fall too. (?) Either way, some people are incapable of safely operating boats, and I think it's kind of lucky that they also seem incapable of getting or keeping them running most of the time. This is the 2nd boat they will have killed in under 3 seasons. Yes, it's always someone else's or the boat's fault (another reason I will stay away from the gong show).