Abstract: Drivetrains and constant velocity joints for recreational vehicles are disclosed. These joints comprise a housing, an aperture for connecting with an axle, and interior components for rotatably connecting the axle to the housing. Various retention mechanisms improve the retention of constant velocity joints, including hydraulic-based, disc-based, pin-based, spline-based, and spring ring-based mechanisms. Hydraulic-based systems utilize adjustable hydraulic pressure for maintaining engagement. Disc-based mechanisms employ a conical disc that provides additional frictional force to resist pull-out forces. Pin-based retention involves drive pads or pins and corresponding tracks or grooves in the shaft interfacing gear. Spline-based mechanisms include a toolless locking half shaft retention system with rotating, interrupted splines. Spring ring-based retention features multiple flexible retaining rings placed axially along the spline, providing improved shaft retention.

Abstract: A method and system for operating a two-stroke engine includes a fuel system comprising a fuel pressure sensor, fuel temperature sensor and a fuel injector and a controller in communication with the fuel pressure sensor and fuel temperature sensor. The controller controls the fuel injector with a fuel pulsewidth determined by determining a beginning time of a window for measuring fuel pressure, determining an ending time of the window, measuring fuel pressure between the beginning time and the ending time, determining a fuel pulsewidth based on the fuel pressure and fuel temperature and injecting fuel into the two-stroke engine in response to a desired fuel mass.

Abstract: A method and system for operating a two-stroke engine includes a fuel system comprising a fuel pressure sensor, fuel temperature sensor and a fuel injector and a controller in communication with the fuel pressure sensor and fuel temperature sensor. The controller controls the fuel injector with a fuel pulsewidth determined by determining a beginning time of a window for measuring fuel pressure, determining an ending time of the window, measuring fuel pressure between the beginning time and the ending time, determining a fuel pulsewidth based on the fuel pressure and fuel temperature and injecting fuel into the two-stroke engine in response to a desired fuel mass.

Abstract: A method and system for operating a two-stroke engine includes a fuel system comprising a fuel pressure sensor, fuel temperature sensor and a fuel injector and a controller in communication with the fuel pressure sensor and fuel temperature sensor. The controller controls the fuel injector with a fuel pulsewidth determined by determining a beginning time of a window for measuring fuel pressure, determining an ending time of the window, measuring fuel pressure between the beginning time and the ending time, determining a fuel pulsewidth based on the fuel pressure and fuel temperature and injecting fuel into the two-stroke engine in response to a desired fuel mass.