What to torque motor mounts at?

I'm wondering what is the maximum torque for the motor mounts on the china motors. My motor wants to tilt a little to the left. Main problem is that the tubes are a differant diameter than the mounts. This results in not a good grip on the tubes. So obviously they do need to be as tight as possible, but what is "as tight as possible"?

i use a small adjustable crescent wrench,regualar small wrenches are fine too(sockets use too much force).
i pretend to be a small girl and tighten my nuts until they are snug. then i grab my engine(still pretending to be a small girl) with 2 hands and try and move it back and forth,if it moves then i tighten one more turn of the nuts and try and move it again. when the engine doesnt move then i add another nut(double nutting) to all mounts and i turn the second nuts only 1 turn until snug(dont want to strip the threads). dont forget the muffler strap,that one you can tighten like a man,if you ever have a mount break,the strap might just hold the engine on the bike.

Your engine should not move at all even when the bolts are barely snug. If your frame tubes are too small, you might want to wrap an aluminum shim around them until they fit the motor mounts.

Cabinfever (pretend you're a little girl) has a good way of saying don't overtighten your bolts. Here''s a good rule of thumb: Tighten until the lockwashers are flat then apply just a little more torque. If that doesn't keep things tight you have other issues. Double nuts is an option but another is to replace the studs and nuts with good, grade 8, Allen head cap screws. You probably won't overtorque them with an Allen wrench and they will hold better than studs and nuts. If your mounts don't fit the frame then you need to adjust for that. A good solid engine mount will go a long way in eliminating vibration and loosening of fasteners.
Tom