This feels like a dumb question, but with this motor, (not running, just in your hand), the motor has an awful lot of magnetic cogging. Is this right? When it is in my 4x4 slash, there is very little coasting. Its not like its coming to a skidding halt, but its not like any of the other Castle motors I have. Runs like a bat out of hell, but this just seems really weird to me.

By "cogging" when out of the vehicle do you mean it feels "notchy" when you turn the motor by hand? Cogging is when the vehicle has a difficult time moving from a dead stop and the vehicle shudders when it starts.

The reason some motors feel "notchier" than others is due to a sintered design versus a non-sintered design.

As far as your vehicle "not coasting" with one motor over another is likely due to either pinion/spur mesh or not calibrating your ESC to your Transmitter after swapping motors.

"notchy" would be a good description. It is just that it is not like any of the other Castle motors we have. Not sure if I like it.

It's a motor with TONS of torque, meant for a heavier vehicle than a Slash 4x4. It's not going to coast like a 540 sized motor. How many lipo cells are you running with it? On 2S that motor will be a dog. It needs 3S (or even 4S) to wake up. If you are only running 2S it isn't really the best motor for your application. Something like the 3800 or 4600 4-pole 540 motors would work much better on 2S in that truck.

To compare, I have a castle 1800KV slinging around a 10 pound SC8. Out of the truck that motor has so much magnet that it is difficult to turn the output shaft, in it if you push the truck it has a notchy feel to it and on a slick surface it will slide the wheels without spinning them sometimes. But at 10 pounds of hurtling death-missile it does not have that notchy feel when you just let off power.

As light as that Slash is compared to what a 1:8 SC actually is you will see some rapid deceleration when you let off the trigger and some massive breaking power. You are using a high KV 1:8 motor in 1:10 vehicle, while it may be super fun to drive it will not be perfect in every way, it is just way more motor than that car is supposed to run. I really thing what you are seeing is what would be expected here.

Lol well put. My wife calls my 3908 Maxx, "The Beast".

I am using 3s batteries in it. Originally I had a 540 sized motor but on 2s batteries it seemed it couldn't get out of its own way. It certainly does get up and go with the big motor. So much in fact my 13yo won't use it, cause he crashes it every time he gets on the throttle. Thanks for the help guys.