I have the FMF powerline and fmf jet kit along with K&N air filter...

I was told to put the '124' jet from the fmf kit in however I find that it bogs at low rpm then backfires a little bit. Should I try the '128' that they supplied me with?

Ill post pics in a little bit I have to install a hardwood floor at a friends of mine.

-Mike

ps how many turns should I have the mixture screw out? I am at sea level and never leave it. Thanks

 

If it bogs right off idle, then the mixture screw is probably too lean.
It should be somewhere around 2 turns out to start with, and then slowly go in and out from there, to find the highest idle, then adjust the idle speed screw back to the proper rpm.
The main jet will only effect wide open throttle. Heres a good article on jetting which should help out.
jetting