For owners of modified 2017-2018 Yamaha GP1800 personal watercraft, GreenHulk Performance has published a detailed guide outlining a preventative reinforcement designed to address a potential weak point in the hull around the intake grate mounting area.
Before diving into the repair, GreenHulk is careful to put the issue into perspective. According to the company, this is not considered a widespread problem. Thousands of GP1800s remain on the water without incident, and only a small number of hull failures have been documented. Even so, owners running significant performance upgrades and speeds above stock may want to consider reinforcing the area before problems develop.
The concern centers on the intake grate insert section of the 2017-2018 GP1800 hull. In that location, Yamaha’s original design leaves a thinner section of fiberglass supporting the intake grate inserts. Under normal recreational riding this generally isn’t an issue, but repeated hard landings, rough-water riding, higher pump loads, and increased speeds can place additional stress on that section of the hull.
Rather than simply repairing damaged hulls, GreenHulk’s solution focuses on strengthening the area before cracks occur. The process involves removing the factory inserts, rebuilding the recessed section with fiberglass and epoxy, and replacing the original inserts with larger Yamaha FX SHO intake grate inserts that distribute loads across a broader section of the hull. The guide also covers the necessary hardware changes, sealing procedures, and installation tips to complete the modification.
For readers interested in performing the upgrade themselves, GreenHulk has documented the entire process with step-by-step photos, measurements, recommended materials, and installation notes. The company has also made the oversized FX SHO intake grate insert kit available through its online performance store, allowing owners to source the required components from one place.
If you own a modified 2017-2018 Yamaha GP1800—or are planning future performance upgrades—the guide offers a thorough look at both the reasoning behind the reinforcement and the complete installation procedure.
You can view the complete tutorial on the GreenHulk forums, along with the recommended parts kit available through the GreenHulk Performance Store.
