go to ebay,under were it says browse for a item, you will see (ebay motors) click on that link.then type rincon in as a serch word and you should see them.there are 2 kinds of tips 1 is (stainless steel) 29.99 the other is (billet aluminum) 39.50. you might want to get some feedback on what one to get all i can tell you is i got the stainless steel one it was cheaper.i am verry happy with it, hope this helps.
It is a private individual that is making them, installing the tip should not affect your carb, if you need a spark arrestor, go to www.promotobillet.com and click on accessories, it is the cone shaped screen. It will fit fine.
after you get the endcap off you will see a groove were a aftermarket spark arrestor could go.it will not fit in to the groove,what i did was just put the cone inside the pipe and the new endcap will hold it in place. a few things to rember 1 soak the 8mm bolts real good with wd40 2 go easy on the wrench. the bolts can snap real easy going off or on. 3 once you get the bolts off use some anti-seize compond on the threads befor you put them back on.that way thay will come off easy in the future. hope this helps