The motor won’t handle the 4s power. The combo isn’t rated properly. The 1406 motor input voltage is 2s-3s. The esc is rated 2-4s. It’s all over the package 2-4s. You call castle and ask the tell you it won’t work long on 4s. Don’t waist money on this combo. The 1412 3200kv is rated for 4s.