Thanks Sparks!! Appreciate it. I combined your explanation with the one below and followed them both. the one below was a little easier since i could just unplug the three wire harness in one quick step, and then toggle through the menu until i got to a flashing WS, where i changed it. I took your advice and went with a 1790.
Unplug the 3 wire plug with red & black & brown wires coming from the speedo.
With the display showing engine hours, press and hold the "mode" button untill you switch to different menu.
Cycle through the options with the button till "WS" flashes. change the wheelsize with the + and - buttons to the circumference of your 17" front wheel (I set it at 1882) then press "mode" again, then hold the "mode" button till it returns to normal display.