Performance pipe needs a performance filter not junk stock restrictive air-box and resonator which acts a governor on a puch moped,
No cone, get Metal mesh filter or run no filter for a bit and see what it does and up jet to maybe 70-72 with 2.22 atomizer, Pretty sure your carburetors is 14 mm Because maxi with open port cylinder most times came with a 14 mm carb with 64 jet 2.22 stock but if 12mm it still could take close to a 70 jet,
You want to have a filter that is almost the same as none restricting wise, you should’ve tried mesh filter or no filter first with stock pipe because I get 35mph an hour just by changing the filter and up jetting on a open port cylinder 2hp keeping the stock exhaust,