First off, to have broken those mounts, I would suspect the bike had been in a very bad accident. I have a similar thing with the 2015 engine I bought. Must have been completely run over by a truck, as the frame was even bent! 3 of the 4 mounting brackets had been broken off at the half way point of the holes. I fabricated some special brackets, installed, and torqued to specs. Smeared some JB weld around one mount, to use as an indicator if there's any movement. Been months now, and no problems.