mouse scroll settings

Need to know how to adjust scroll wheel down with Java program in Firefox browser.
I'm trying to use a genealogy extraction program which provides me with U.S. census data that I in turn help digitize for it's redistribution/use. It's written in JAVA for the most part and so far it works except for being slow and a little flaky/unpredictable and scroll feature on mouse is not adjustable in their menus.
The slow/flaky/unpredictable are a given in Java I presume and maybe more so since Linux is not supported by FSI.
One click of the wheel renders 7 lines of text scrolled in FSI. I've used Mozilla Firefox about config and settings in the menu system which changed the amount of lines scrolled in everything else but this Java program called family search indexing. Also tried other browsers Opera, SeaMonkey, and Epiphany.
I've asked for their help and all I get back is we don't support Linux but you should be able to access control panel and adjust settings there. I understand that KDE has such mouse settings available. Where might they be found in Gnome? ADD 2 WISHLIST %:)SW