Yoshi Racing Story 64 is a Mod (hack) that features Yoshi as a playable racer. Green Yoshi replaces Timber and Red Yoshi replaces TT. Red version has TT stats for more speed and is a smaller scale. It also has 4 brand new levels in a Yoshi universe theme.
Here´s gameplay video by Snooplax
You need the xdelta program. Please see the tab applications if available.
Recommended Emulator for n64
Acess to download on n64vault