Sorry about your luck, this wouldn't be the first time I've heard about this from a Tekin RX8. For the future, make sure you're not using the deans (T) style plug as they're not that great for 4s. I've had my buggy shut down because the esc got hot, I found out it was the deans plugs I was using. They don't pass enough amperage through them and it makes everything hot, from the battery to the esc to the motor. I second the Arrma blx185 for bashing purposes, it's a great and inexpensive esc that'll run a 6s lipo and it's waterproof. Sadly, tekin just isn't what it used to be. I've heard a lot of issues from their equipment lately, let's not get started on their Gen 2 products.