I ordered 4 engines. Motors with white nuts did not work. I thought about opening a dispute. The problem was not washed flux on the contacts. He warmed up the contacts with a soldering dryer and wiped them with alcohol. The engines started working. Also, the white engines did not spin when starting 30 seconds, but twitched as if in an epileptic fit. I turned them off and on several times. After a minute, they started working normally. There were no such problems with engines with black nuts. They started immediately. Conclusions - very bad build! The order was traveling for a month.
I ordered 4 engines. Motors with white nuts did not work. I thought about opening a dispute. The problem was not washed flux on the contacts. He warmed up the contacts with a soldering dryer and wiped them with alcohol. The engines started working. Also, the white engines did not spin when starting 30 seconds, but twitched as if in an epileptic fit. I turned them off and on several times. After a minute, they started working normally. There were no such problems with engines with black nuts. They started immediately. Conclusions - very bad build! The order was traveling for a month.