Stuttering for the first second or so
 

Kyosho ZX-5
Novak 7.5 brushless motor (bought second hand but not used much)
LRP SPX ESC, brand spanking new
Acoms 2.4ghz receiver and tranmitter
5100 Orion NIHM batteries

I'm not sure exactly what's wrong, all I can explain is that on forward and reverse, the car seems stuttery for the first second or so, then it takes off.

With the motor out of the car and not connected to anything, it seems to run smoothly enough.

I've tried a brand spanking new 9.5t brushless motor (LRP), and it does the same.

Anyone any ideas?

have you tryed a different sensor cable? is the car drivetrain in good condition?

As he said, try a new sensor cable, if that doesn't cure it, try a different motor

The stuttering is usually down to the rotor not being lined up with the magnet, you tend to get it more on sensorless motors, but most motors used for racing are sensored.

http://www.oople.com/forums/showthread.php?t=42104

not just sxx but spx aswell

My SPX doesn't beep at all when you switch it on?

I think I might have found the problem. I did notice that there was a slight scratching sound when turning the wheels. So I've took it apart and it looks like one of the bearings could be knackers. I think the bar through the spur etc is slightly bent.

Here's some large photos which kind of show some indication of something not right. As you can see, it looks like the outer part of the bearing has also been turning inside it's holder, hence the black plastic everywhere.

Hopefully that's all it is. You wouldn't think the cars only been raced once!

http://www.web-development-server.com/DSC_0178.JPG
http://www.web-development-server.com/DSC_0179.JPG
http://www.web-development-server.com/DSC_0180.JPG

I've just been onto JE Spares and ordered a new bar and teflon bearing, hopefully that fixes it.

In the meantime I'll look into the ESC issue. See if I'm affected. Not sure I am because I seem to experience the stuttering at low throttle, rather that at full throttle.