Jimmy Riddle

Hello Yamaha owners. My 1994 Yamaha Sr125 workhorse finally gave up on me last week. There’s still combustion and the clutch is fine but the transmission/gear-set is buggered. I’m going to swap engines. Will a ‘96 engine, for example, fit my ‘94?? Is there a way using websites, registrations or serial numbers that I can use to cross reference engines with chassis’ to confirm compatibility?