Found these speed mods on the Internet for a Raptor 50. I will be trying them soon and update this thread for accuracy and with pictures.
- Rejet and modify carb: rejet carb, main jet 80, pilot jet 12.5. Replace the slide with part# 2HX-14112-35-00 also need to replace main nozzle with part# 2HX-14141-78-00.
- Remove the two screws on throttle housing, you will see a gold bracket you need to replace with part# 36B-2625H-00. NOW YOU HAVE FULL THROTTLE!
- Remove all of the air cleaner assembly and install K&N air filter with outerwear.
- Replace CDI box with any aftermarket unit that raises the electronic rev limiter.
- Replace stock size rims/tires with larger rims/tires for more top end and smaller tires/rims for more low end.
With a combo of these mods its been said you can make a Raptor 50 hit 30mph and beat a stock Raptor 80 or 90.
These are all basically Raptor 80 parts being put on the 50.
Good people to talk to about these mods are Raptor 80 Racing - Performance Parts for Yamaha Raptor 80's