http://www.2strokeworld.net/wp-content/uploads/general-tech/tech-jetting/davefmod.pdf
Some additional instructions with pics
https://files.secureserver.net/0sxTWBlyTWlOB6 (https://files.secureserver.net/0sxTWBlyTWlOB6)
FYI; I was unable to download using Microsoft Edge. Internet Explorer 11 worked fine.
This was already posted here quite a while back THE TECH LIBRARY »CARBURETOR - FUEL/AIR DELIVERY (http://www.2strokeworld.net/forum/index.php?topic=54.0)
Some don't show you should use 159 needle jet for the 400.
Thanks, Mark. Such a great mod from either stock or modified bikes.
https://www.economycycle.com/shop/yamaha-rd250350400r5ds6ds7-parts/fuel-and-airintake/carburetor-rebuild-kits-parts-related/popular-carb-mod-kit-for-rds/
Remember to support EconomyCycle and use the discount code! "2SW"