Think I could shove an a35 up in there? With some fabrication, of course. Or would the frame be too heavy?
Changing motors wont help with the titling process, the vin will still be to an MX100. Unless your plan is to put a tomos vin on the head tube or something which i wouldnt recommend. If you did that, you would be left with a slow moped engine on what should be a faster dirtbike and dealing with weak clutchs and other moped issues.
Not to mention the DT/MX motors are good engines. Simple to work on and fairly cheap to repair.