I've got an older XL185S roller that I was toying w/ the idea of putting a 200X motor in. Aside from backwards kicker, I think it'll work- I had an '82 XR200 twin shock that was an absolute blast to ride in the tight twisties,but it was stolen a couple years back, & when a buddy offered me this roller I took it! Any one of you guys ever try anything similar to this?

 

besides the kick starter like you said......I cant think of why it wouldnt work.
the 200x wont have a twist throttle carb setup
I'm not sure, but you may need all the wiring off the 200x trike also, I'm not sure how the XL wiring is set up.