The tubes the FlexJets run through melted/disintegrated after about a year after install. Installed along with the H2W jetting and pre-filter kit.
I would suggest replacing the stock tubing with a thin-wall fuel line (the transparent kind) at the time of install to avoid having to do this later.
For me, after initial setup for my home elevation, they have been more peace of mind knowing that if I ever find myself in higher elevations I'll be able to adjust things to suit the situation.
As for utility, I've ridden from near sea level in Texas to the top of the Smokies (dirt and paved roads near the Cherahala Skyway, Dragon, BRP) and not felt any need to tweak things. I can see myself making a Colorado trip that could benefit from this adjust-ability.
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