This one way starter clutch gear assembly with bearing and flywheel is designed for use with TRX400EX and 400 EX models from 1999 to 2008, as well as TRX400X models from 2009 to 2014.The component functions to engage the starter motor with the engine crankshaft during ignition and disengage once the engine is running.This part is intended to restore equipment functionality and fitment specifications.Compatibility is limited to the model years and designations listed in the product title.Installation should be performed according to standard mechanical procedures for motorcycle engine components.