Gugman That is the price for the pinion gear only. If you get the motor the pinion gear is already on it with the motor mount as well.

Gugman No, as the Transmitter only has a throttle Trim option. Your only option would be to get the 3-in-1 Receiver Board and Transmitter that the 284131 uses or the ones for the newer 284010 and 286131 as they have a Throttle Dual Rate option where you can set a lower top speed. The new 3-in-1 Receiver Boards are the same size and look as the one in the K989 but have an updated Transmitter with better Steering and Throttle control. Also, both of the Transmitters will work with the new Receiver Boards as the only difference between them is the 284131's Transmitter uses 4XAA batteries and the newer 284010 and 286131 Transmitter uses 4XAAA batteries.

Gugman Thisis a question that has been asked around 6 years ago now and the product page is not available anymore to even find out anything about it. I have never even bought this and I keep getting these sorts of product questions to try and answer that are not even listed to buy anymore and are utterly pointless in giving any kind of answers for them.

Gugman Apparently,it does.

Gugman They would most likely fit but the motor comes with the pinion gear and mount fitted already. The Loctite they use on WLtoys is a real pain to try and remove those parts as the motor mount is for the 124016, 17, 18, and 19 and is different from what used is in the 12428. Also, you will need a new Transmitter and Receiver for the Brushless ESC since it is not a 2 in 1 ESC like the 12428 uses with its Transmitter.

Gugman I suppose if you buy one you can do whatever tests you like to it. As for whether will it run after breaking it would be the same for anything else when it is broken. Usually no as it is broken therefore it will not run or work anymore.

Gugman This motor is for a 1:12 scale car and the Flyhal 9135 is a 1:16 scale car and it would need extensive modifications even trying to cram it in there as the motor mount and pinion on this motor are a real pain to try and remove. You would be better off looking at an ESC and motor combo from Surpass Hobby that would be more suitable for a car of that size.

Gugman 3.175mm.