Performance Modifications 2005 trx 450r jetting help September 11, 2015 I have a 2005 trx450r. With a 12:1 compression piston full HMF competition series exhaust and a K and N air filter with outwear but no air box lid. What jets and needle adjustment do I need. I love in clarion county pa Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related