have a 36 v 500 watt motor on 26 inch front wheel, [wife got ] .no name on motor just number, [500 wsydg 73626 ik0093] trying to get as much info on it before i open it up,

as i hear crackle and wheel judders when apply power to it, hopefully just loose wire.

Post photos. Is it a brushed or brushless? Sensored or sensorless?

moter is brushless sensored [ATTACH=CONFIG]4602[/ATTACH][ATTACH=CONFIG]4603[/ATTACH]

have a 36 v 500 watt motor on 26 inch front wheel, [wife got ] .no name on motor just number, [500 wsydg 73626 ik0093] trying to get as much info on it before i open it up,

as i hear crackle and wheel judders when apply power to it, hopefully just loose wire.

 

You don't need to open up the motor yet. Almost certainly you have the wrong phasr and/or hall combinations. The first thing to check is that the colors match on each side of the hall wire connectors. If everything is OK there, then you have to go through all 36 combinations

DO NOT USE FULL THROTTLE TO TEST. With the wrong combination the controller can give huge current that can damage things. One combination will make the motor run backwards. If it has a clutch, you,ll here it but no rotation. You can get the correct rotation then by reverding any two phase wires. Try all combinations to find the one which runs the smoothest. Beware of false poditives that run stupidly fast or a bit rougher.

will try that tomorrow ,seen a chart some where to mark down the diffrent combinations , so dont get mixed up/thanks d8veh.

was about to try difrent combinations using ku 123 controler. noticed paper seal on side broken, looked closer seen plastic seal not seated properly so took off screws just as well i did, in side seen p c b sitting at an angle most of it tuching the casing .this was a new controler from B M S . had i powered this up it would have blown [, repaired ku 123 ],tried combinations motor now running .THANKS d8veh.

I agree with other posters...juddering and sudden stopping or very short movement with an abrupt stop does sound very much like a poor connection somewhere (most likely between motor and controller, or controller and battery, rather than anything inside the actual motor). I've experienced this myself a few times.. the crackling noise also makes me thinks bad wiring connection somewhere or dodgy connector probably from the battery or on the main power to motor..somewhere where there's a lot of current passing!