This project is an intake manifold for Kawasaki piston port 550 jetskis. Mid 2025, I decided that I have too much time on my hands because I decided to buy a 90s jetski. Although they are very fun to ride around, they are an endless pit of tinkering for someone like me. My curiosity and never-ending desire to improve designs led me to take on the task of manufacturing an intake manifold for the larger Mikuni SBN 44 carburetor. This is a popular upgrade to make more power in these jetskis but requires an aftermarket intake manifold. There are many on the market, but none that fit all of my criteria for a good design for a 2 stroke motor. With a 2 stroke motor, in order to make power you want a small intake and crankcase volume, as well as a fast and aerodynamic path for the air fuel oil mixture to flow. This gives you faster throttle response and allows you to make more power faster. Another issue with the factory jetski carb placement is they use a downdraft carburetor, which causes a 90 degree turn for the air fuel oil mixture to make. This greatly reduces flow and aerodynamics. My criteria for the manifold was the lowest intake volume possible, around 120 cc. I wanted to angle the carb slightly out to improve the flow of the mixture, add vertical veins in the flowpath that serve a similar purpose to wing fences to make for less turbulent flow in the path of the mixture and have the split for the two cylinders closer to the carb face to reduce turbulence. This is something that will also be designed with the aid of CFDs to make the most efficient shape. As to the manufacturing of the product, normal FDM wouldn't cut it, as the plastic would degrade quickly with fuel and heat. I decided to look into 316 stainless steel. This design wouldn't be conducive to CNC machining, as the walls vary in thickness and the tool path would be impossible to create for some parts. That's why I am working with a company on a 316 stainless 3D SLS printed part, making it so I can use complex geometry and have a very efficient piece in the end.