This is what you need, fits straight on and no more stripped pulleys, I would fit new belts when you add this part
http://www.stellamodels.com.hk/84391...ey-p-8566.html
Description:
Tamiya Hop-Up Options
Usable with :
DB01 *Use with Item 54018
TRF511, TRF503
Attached in place of kit-standard resin parts, this aluminum 1-piece 18T pulley has great durability and its anodized finish cuts power loss.