My 1994 150 Johnson Ocean Runner popped into neutral under power and left me floating on the calm waters of Matlacha Pass in SW Florida today. I had to be towed in because forward & reverse do nothing. It looks like the shift rod is moving up and down properly below the carbs although it's hard to get a good look at it. I've never had any problem with it and there was no unusual noise when it shifted into neutral. Before I remove the lower unit what might I check?