LRP X12 motor running problems

[Team No Idea]

Hey Chaps, Im having a bit of a nightmare getting ready for maritime's Off Road Wars this coming weekend.

I ordered a new 8.5 LRP X12 motor and fitted it last night to my Nosram pearl istc. I have run this car with the nosram every week for a few months with a Novak Ballistic 13.5 with no problems. However now ive fitted the LRP the car judders like buggery (i think its known as cogging) form initial take off. So i tried replacing the sensor wire, i altered the motor timing, reset the speedo, and adjusted the throttle end points on the transmitter.........Its still messing around. So i change the speedo to my spare Hobbywing 120a, still hte same issue. So i change the motor to my 10.5 LRP and my Nosram pure 5.5 motors, still the cogging issue.
So finally i install my 13.5 novak and hey presto it works!
Any ideas chaps?

[Jamie.T]

I had the exact same issues last week with an LRP Sxx and X12. I too also tried a different ESC and sensor wire and it was still cogging. After reading RCtech it seems like a very common issue, but unfortunately with no real fix.

Instead i fitted a different motor and ESC and it now works fine. I would love to know what was actually causing the issue. It doesnt seem that LRP ESC's and motors are compatible.

[spud31]

Dude try reshimming the rotor closer to the sensor board this is the usual cause of this.

[stoff]

While you have the motor apart check that the three solder points on the front haven't desoldered! X12s run hot and can melt the solder causing poor connections

[JBL]

Does it just seem noisy at low speeds and does it clear at high speeds? When you let off the power is it noisy?

If the above does happen this is a normal sound of a X12, this is purely down to the rotor generating alot of magnetism from the magnets within the can. I found running a high rev/low torque rotor for the X12 has cured the noise and made it easier to drive in all conditions.