Join Date: Feb 2015
Location: southern oregon
it wont cause any harm as long as you can keep it away from the plastic. it would not be "tuned"the the yfz but that is mostly bs anyway. if you are not planning on opening the airbox and re jetting it is a waste of time. it will be louder and thats it. the factory mufflers on a yfz are not horrible and the worst of the restriction is in the air box. it does not matter how much flow your pipe has if the air box does not flow. i have a stroked and bored (501 cc) with a full port and polish and i just run one of the 100$ dg slipons with no problems. before i did the motor work it was faster than my other one with a full fmf. long story short i dont think it is worth the time to fabricoble your gsxr pipe on. open the airbox, install a dg jet kit, a flex jet air screw and a 100 dg slip on and you will have a whole new machine for less than 250. if you want to do the air box let me know i will show you what i did .