I emailed Indmar about the fogging procedure for my engine and they sent me the same winterization pdf that CantRepeat posted. I also called one of their "Platinum" service centers and the gentleman there also said to fog through the spark plug holes. He said that the problem with fogging through the intake is that the oil is not supposed to get onto the MAP or throttle position sensor. It could cause the sensors to not read properly. So, I get to worry about that all Winter. (On cars the MAP sensor is usually in the tube between the air filter and intake. Does the MCX even have a MAP sensor?)
The thing that makes me mad is that I pulled the engine manual from the Indmar website and it specifically lists the "MCX 350" as an engine that the manual applies to. Then it tells me to fog through the intake. I literally did things "by the book" and still got it wrong
I don't even see where the "winterize pdf" is even published on the Indmar website.