unless you get a package with the hmf it will not come with a airfilter or jet kit. if you are uying one strate from hmf it will not come with the jets and air filter. it is not hard to rejet it just takes alot of time to get it right. i have rejeted alot of bikes and its prettty easy now. i had a tractor muffler on y rubicon and i really liked it.
-Aaron
-Aaron