planning on doing a ms660 big bore kit, what do i need to make this possible?

[Street Ryderz]

When you say stock, I'm thinking unported and with regular restricted muffler and NT carb, but the MZ Pipe gives decent Flow of exhaust leading to the throttle response or does it help hill climb, if so you sold me Mr Salesman.. I'm getting a CR80/WC80 pipe and welding that sucker in

When I state it's stock then yes no port timing changes just cleaned up the flashing or bad casting,stock crank untouched,stock nt carb with a #72 jet,stock head untouched,stock gearing and all I did was put the MZ pipe to see how it would do.The MZ pipe is ok but also has some issues a kx or yz pipe is much better or better yet is a scooter pipe with broader power band better suited to street use.