Hey RB—-It’s interesting that your boss had the same issue with his XL2400….I say that because when I limped back to the dock after breaking down I just happened to a see a Seasport 24 tied up and noticed that the gas caps were mounted up on the wheelhouse walls —my first thought was —if my caps were mounted vertically and off any surface that could pool water, I’d be out fishing, not having to belly up to the bar with $2K in hand to get all my filters changed out, injectors cleaned , and VST’s drained
So here’s what I know—-Perko caps have a KNOWN issue. They even include a fine-print add-on that warns installers not to mount the caps where water can pool. Gas tanks expand and contract and when they contract they create a vacuum that will suck standing water through the Perko caps and down into the tank.
Perko offers a “riser” that is designed to shim the caps off whatever flat surface they are mounted to. I tried to install the risers last summer but I couldn’t get at the hose clamps under the deck to loosen up the filler tubes (at least without cutting fiberglass which is beyond my pay grade) so I gave up
NMI (Northwest Marine Industries) is a stand-up company. They stand behind their products and if there are issues, my experience is they will help to address them.
You might have your boss call them. I mention that because as mentioned above, it was explained to me that the charcoal filters (for vapors and overflow during refueling) that are now mandated by the EPA will clog up which only exacerbates the tank expansion and contraction issues (no venting!) So couple that with a crappy cap that leaks and you can see how both rain and salt water splash are getting into the tanks
If you want a private contact for NMI, PM me, especially if your boss has a newer XL2400