Well yes, Your going to need a air filter adapter of course. It usually comes in a kit with a header, filter adapter, filter and a larger main jet. Here is a excellant kit here.
http://www.affordablegokarts.com/mm...re_Code=A&Product_Code=BK1&Category_Code=BOK1
looks great gonna try it on my old 4hp! i also dont know where i could find a place where does exhausts without a muffler on it where they send it to england or is in GBP £ ? could any one help?
Just cut off your old muffler and use that exhust flange. Then find a pipe and weld it to your original flange. All you need is a pipe and a weld.
Thats all I did in the pics above. That short pipe you see hass baffles in it. So not really a strait pipe.