on my blaster i have a fmf pipe and sil. k & n filter outerwear. what size jet should i use if i am at 30 ft elevation. yes 30 ft. thanx

 

I would start with two sizes richer on your main jet, your jet needle in the 3rd position. and do a test ride & plug read. Depending on the plug condition, go from there as to leaner or richer on your main jet. I assume you know how to correctly do a test/plug read, and what a correctly jetted plug should look like?

 

BLASTERMXRACER,
That reply is about as close as you can get without actually testing, since jetting is not an exact science like mathematics. Only YOUR engine can tell you what it needs, and the jetting others may use is only what their's needs.