I WAS WONDERING IF ANYBODY OUT THERE HAS MODIFIED THERE STOCK EXHAUST BY MOVING THE EXHAUST PORT FROM THE BOTTOM TO THE BACK OF THE MUFFLER. I WAS THINKING OF DRILLING A 1-1/2 OR 2 INCH HOLE IN BACK AND WELDING A PORT ON AND WELDING SHUT THE FACTORY ONE. I WAS THINKING THIS WOULD HELP EXHAUST FLOW ? LET ME KNOW IF THIS CAN BE DONE OR IF I HAVE TO MUCH TIME ON MY HANDS.

 

Why waste your time in something that will do very little. Just buy a slip on and be done with it. The most performance that you will get out of an auto 4 stroke would be in the clutch. This is where your biggest gains will be. Change the primary spring and it will perform much better.

 

My friend did the same thing on a scrambler 500,he made a 2 1/4 hole in the back gutted the baffle inside then added a turn down piece.He also did the K & N filter at the same time,he went up 3 jet sizes.He also installed some different clutch weights,and man it woke it up big time.

 

I have done what you said plus I left the factory port to. I did see some better performance but nothing huge. Look at my pics of the modified stock exhaust.