It's best to use a K&N air filter or stock. Then troubleshoot the carburetor. Take a method approach. First open the carb and see what size jets are in it. Main and pilot. Then talk to Lancer about a upjet kit probably 2 to 4 sizes up from what's in there now. Also do the needle valve washer mod with 1 or 2 washers. It's going to be trial and error but you can get the jets and needle out with the carb in the engine. Just pull the fuel tank off for opening the top of the carb. And don't drop any screws.
That's it! Good luck and no real magic is needed.