I believe that in addition to the mounting bolt pattern being different the CT200 frame is narrower which would prevent the CT90 engine from being mounted. With enough welding, grinding, fabrication you could make it fit but it'd be a lot of work. A Lifan engine will probably bolt right into the CT200 frame with a little grinding possibly required. Then of course you have to make changes to the wiring, muffler, intake, etc..

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Q (Quantum Mechanic)

1968 CT90/140
2007 Lifan 200
2005 Zongshen 200
1981 Honda GL500 Interstate