I am sorry but the CD200 is twin cylinder and cannot be installed without some major modification to the chassis and changin the characteristics of the bike.
if you can find a CB180 engine and transmission it is simple bolt on job and fits perfectly. Actually there have been a lot of these modification already done. I personally modified a Paggio Vespa Super 150 and C70. I put piston, head, and cylinder of a sprinter scooter into the Vespa with bigger jets on the carburator and it turned out to be faster then the Sprinter and gave Cg125 a run for there money On the C70 I bored the it to 105cc again with bigger carburator from the honda 100 but it chewed the tranny after a lot of abuse. The vespa is still running used buy my Susar (father-in-law) he loves the extra power, lol!