sorry guys, i'l explain it better.
you remove the end cap from the exhaust using allen wrench.
remove the spark arrester, it is spot welded to the end cap, dont harm it!
you cut off the 3/4 inch exhaust tube coming out of the end cap.
open up the hole in the end cap to fit in a 1 1/2 inch pipe, from any auto parts store.
weld in the 1 1/2 inch pipe, trying to keep it looking like the stock one you removed.
slide the spark arrester back onto the end cap, and either spot weld it on, or leave it, bolting it back together will hold it on.
now, with the end cap still off, look into the back of the exhaust. about 7 inchs in there are baffles.
slide in a 1/2 inch drill bit, and start drilling holes in the baffle. i put in about 10.
this allows more air to move through without harming anything.
DONT DRILL THROUGH THE SIDE OF THE EXHAUST.
now, reinstall the end cap with the spark arrester in place.
you just took a baffles exhaust and opened it up, allowing more air flow.
this will not hurt the exhaust, or engine, as long as your not lean.
the differance was going from a light front end on full power to flipping mine over with full power.
it works, and its cheap! many have done it, and not one has regretted it.
good luck, hope i helped.