Does anyone have any insight on one of these hydrofoil stabalizer plates that mount on the motor above the prop...What is their purpose exactly and do they help that much...My other question is about a stainless steel prop...I have a 18ft statos F/S with a 115 Johnson with a factory prop... Will a good SS prop help that much....thanks    darren

Yes a SS prop will be better. You will get a better hole shot and better speed. since a SS prop does not flex like a Alum. prop. the SS is well worth it.

The stabalizer.  does your boat have a planning problem? If not they will not do you any good. they help to plane the boat out faster. On my small 14 footer with 15 Hp they help out greatly. without them the boat will not plane. on my 17'6" with a 75Hp they do nothing really.  The boat planes the same with them or without. Infact I just gave those from my 75Hp to a friend who has  17 foot astro with a 115 Merc that would not plane. They work good for him. His boat planes out now.