The starter motor sits on top of the engine cases behind the left two cylinders (as you sit on the bike)
If you look at your engine from the left, look between the cases and the carbs and you will see it. It bolts to the top of the cases right about in the middle, and plugs into the cases behind the left crankcase cover.
The parts microfiche does not do a good job showing where the starter motor sits.
http://www.babbittsonline.com/pages/parts/viewbybrand/default.aspxIf you go through the steps of putting in your brand, motorcycle, year and finding your model, then select the crankcase option, where you see reference #27 is where the starter motor nose cone is installed in the cases. If you look towards the center of the cases behind where the cylinders are, right between where #2 and #3 would be, you can see one of the castings sticking up that is used for mounting the starter motor to the cases. Also, in the small diagrams at the top of the page, the left diagram shows a short line extending perpendicularly down from the row of cylinder holes, just to the right of the #2 cylinder, that is another view of where your starter motor attaches to the cases.