Broken Engine Mounting Bolt

6mm dia. and 1.0mm thread per mm hope that is the way its supposed to be as I went and used my metric thread gauge. If you have to you can drill it out over size and go American threads I won't tell I'd do both or even all of them and be done with it. good ol American nuts and bolts. No I didn't do it haven't had one break on me. I have had the heads nuts strip trying too much compression and blew them loose. Makes it whistle like a steam engine.
Norman

i keep my bolts snug using pliers and i dont use a lot of pressure.
double nutting almost always keeps the nuts from coming loose.
and nobody wants there nuts coming loose,lol.

or going through the spokes!

well since i changed bikes i did have my gas tank nuts fall off and a rear engine mount stud vibrate out,but my engine stayed on the bike and ran ok enough to get it home to tighten everything and put stud back in.

my other mounts and muffler clamp held the engine to the bike ok,chain loosened up a little but stayed on too.gas tank still was being held on by 2 nuts.rear fender kemp stud from sliding all the way out.