I have a 1997 voyager with 250 ox yamaha and a 9.9 yamaha high thrust kicker ( 1997) I use it mainly for an insurance policy if the big motor quits. I have used the engine on harbor tours and it gets the boat up to 6 or 7 knots in smooth water and or one foot waves--I have not used in bigger chop and higher winds. Some say it is a waste of time but I feel it could help in a pinch. Lew