Fuel starvation and unexplained power loss can send PWC owners searching through the usual list of possible culprits, but Kawi Performance’s Steve Ciervo is pointing Kawasaki owners toward a restriction hidden inside the Gen 2 plastic fuel pump assembly.
In a recent tutorial, Ciervo walks viewers through the fuel pump assembly used on Kawasaki models including the STX160 and Ultra 310, showing not only how to test the system but also where a small internal screen can become another potential restriction in the fuel-delivery system.
The assembly used for the demonstration came from an STX160 that had experienced power loss. Ciervo begins by bench testing the pump while simulating fuel flow at full throttle, monitoring both fuel pressure and amperage draw before opening the assembly to investigate further.
And once it comes apart, the first problem isn’t particularly difficult to spot.
The small pickup bag is heavily contaminated with debris and, as Ciervo demonstrates, substantially clogged. He notes that when a bag reaches that condition, the restriction can put additional stress on the pump and recommends replacing both rather than simply cleaning the assembly and putting it back into service.
But that pickup bag isn’t the only restriction Ciervo wants owners to know about.
Deeper inside the Gen 2 assembly is another fine screen designed to catch small debris. Ciervo points out visible contamination inside the assembly and explains that the internal screen can also become clogged, creating another potential source of restricted fuel flow.
That’s the problem his bypass procedure is intended to eliminate.
Ciervo demonstrates drilling and tapping an access hole into the side of the plastic assembly, then carefully breaking through the internal screen to remove it as an obstruction to fuel flow. The newly created access point is then sealed with a brass plug and the assembly is thoroughly cleared of debris before being put back together.
For owners using Kawi Performance’s DW fuel pump modification kit, Ciervo recommends combining the modification with an inline fuel filter, moving the filtration duty away from the problematic internal screen. Kawi Performance offers its fuel pump mod kit for the 2022-and-newer Ultra 310 as well as the STX 160 and Ultra 160, with both Kawi Performance and DeatschWerks fuel pump options available.
Just as importantly, the video doesn’t end when the tools are put down.
Ciervo returns the modified assembly to the bench-test setup to see what changed. After reassembly, the system holds approximately 43 to 44 psi — right around the 43 psi Ciervo says it should produce — while showing normal amperage draw and strong fuel flow.
Kawi Performance also plans to offer a kit containing the components needed to perform the bypass for owners who don’t want to source the individual pieces themselves.
For Kawasaki owners chasing fuel-delivery issues — or those already planning to have a Gen 2 plastic fuel pump assembly apart — Ciervo’s walkthrough offers a close look at one small component that could create a much larger problem.
Check out the complete Kawi Performance Gen 2 plastic fuel pump assembly bypass tutorial below.
