ORIGINAL: 72
I used the bolts that came with the engine and even ordered more factory bolts from my dealer. They are for sure 5mm bolts.Wirelocking them has fixed it .
If you can get to the bolt heads, I agree that's the best way. I safety wired my ZDZ 50NG's with Supersonic mufflers. No thread locker needed. Just snug them and wire them.