I have a 1999 25hp merc. This motor has the shift in the tiller handle. It will shift in and out of fwd and reverse but will not shift into reverse. I really don't know alot about this style shifter. I was told that the motor has to be running to shift into reverse(because of vacuum). I have tried this but still does not work. It seems as though it's bound up or something. It just will not go. I don't want to force it. Any ideas???