Hi,
I went with the universal Motion Pro throttle tube too. Everything is good except there is no provision for holding the stock throttle cable to the cast housing. My first experience found that the cable was over extending and then not returning so pegged throttle ... not good! I then put a cable tie to my clutch cable and then controlled things pretty well but I wasn't happy with it. First I didn't want anything restraining the clutch cable and making it harder to operate. I also wasn't sure that my cable tie wouldn't slip.
What i ended up doing was drilling a hole in the casting. there are actually two flat spots when you look at the inside, in the correct position. I drilled a 5mm hole, used a shortened original 5mm screw from the throttle, thread locked a nut to the outside and bent the restraining tab a little. The pics show it all. The first one was the cable tie I mention which I've now removed.