If you're only putting a slipon on, no it's not necessary. If you're also putting in a high flow filter on or decide to do a full exhaust system you should definitely re-jet.

 

im at 800 to 900 ft elevation 95 f3 with a uni air filter and d&d slip on with no problems not rejetting....... was like that for years small crackle and rarely a pop off of wide open throttle then letting off but i did just turn my fuel-air mixture screws out a turn to richn her up alittle which should clear it up....

 

ok great, i had heard from a friends that i would have to re jet but they weren't absolutely sure, thanks guys