Haibike yamaha motor noise

Hi all....Martin here.... I have just recently purchased a second maybe third hand haibike sduro hardnine rc 29....with 1 or 2 issues, the seller told me the lcd screen was flashing and there was a clunking coming from the gears/motor possibly both faults linked together...I did a little research online and found that a faulty connection on the mounting plate can cause this problem so I took mounting plate to pieces and checked continuity between the the contact and the solder joint on the inside of the mount....low and behold one had no continuity so I resoldered it and now have a fully functioning display.....I was hoping that would solve clunking...but it hasn't ....
The noise is coming from the Yamaha synchdrive motor I think and if you pedal with no assist on then there is no issues at all...as soon as the assist kicks in a knocking noise starts, there are approximately 6 knocks per revolution of the pedals this model has 3 levels of assist and the knocking seems to get louder the higher the assist ...I think the assist is working OK as you can defo tell you are getting more power when you up the assist levels...as this is my first ebike though I really haven't any experience to say it is working 100% ....the only other thing that I think? Maybe related to noise is when you push bike backwards you can feel a notchyness like something is catching....I think the bike is around 2015/16 and I am guessing that it is the synchdrive motor as it has the double chain ring at the front.......thankyou in advance.....Martin

you should ask this man.he has a lot of youtube videos also. https://www.performancelinebearings.com/

Good day people…just a little update I took the motor to pieces and found a PLASTIC ….main gear assembly which had a few broken/mashed teeth…..I had watched the videos that performance line bearings have posted online on how to take your motor to pieces (excellent videos) (thank you 1boris) and then contacted them and they sell replacements….arrived less than 24 hours from ordering and happy days fixed the problem……cheers hope this helps…. Martin