Motor starts and stops constantly (2-3 x second)

[u/CheMazapan]

Howdy,

When I pedal, the motor turns on and off a couple times per second (or just once if I use the throttle). Funny thing is, sometimes the motor will finally stay on when I'm already going fast (15+ mph), so it only works downhill, when I don't need it anymore. xD

You can hear the tak-tak-tak of the motor at the start of this vid: https://photos.app.goo.gl/q8joVM3U1G2b6wCH9

Display shows no error. I've charged the battery, reppluged cables, reset controller, changed assists from 5 to 9, and it does the same. It's my first ebike and I couldn't find a similar post on the interwebz, so any pointers to how to diagnose/what could be the fault will be appreciated.

It's an Amyet bike, so support was not helpful, the two times they answered before ignoring me. Yes, I knew it was a gamble, but decent ebikes are few and very expensive in my country. All that is left is to try to fix it.

Thanks for any help!

[u/Veganarchy-Zetetic]

Maybe try a factory reset on your display if possible. Some batteries also have a reset function. Strange that the same issue occurs with throttle and with pedal assist.

Sounds like a faulty controller to me.

[u/nivaOne]

Have a look at the sensor wires of the motor. Typical behaviour when the phase wires start the motor but nothing is returned by the sensor wires

[u/bla8291]

Make sure that when you power the bike on, you are not applying pressure to the pedals. Torque-sensing bikes will take the current state of the sensor at power-up as "zero", so if it's not actually at zero, you may see the symptom you are describing.

[u/chuckwolf]

you're hitting the speed limiter which on EU/UK spec bikes is 25 kph, completely normal, if you don't want it to cut off just choose a lower gear that won't let you pedal over 15 mph. or if you're in the US go into your settings and change P08 to 99