Need help keeping motor from moving...

[pumpkinfish]

Hi guys. I had major issues with my MBX6 conversion today. In two different heats, the motor moved away from the spur enough to not make contact and I had to abort the run. I managed to get one good run, then it moved during the warm up lap for the main and I had a DNF.

I am running a Medusa motor with Mike's Mugen mount. When I had my 777 with the RCPD mount, I never had a motor move. I have tried blue loctite on the screws and that didn't help much either. It is always my top screw working loose and then the motor pivots away. I am wondering if there is a screw with serrations or a lock washer I can get into the groove of Mike's mount. I actually liked the RCPD mount in that the whole face was flat and I could use different headed screws. It seems like Mike's is made for cap heads only.

Please help me as I want to finish a race!!!