i am trting to mount my o.s. but i think that the bolts are too short. The bolts only come about 1 third of the way into the locknuts. what should i do? Surely Hangar 9 wouldn't give you this bad hardware would they?

You can get longer bolts at the hardware store or the hobby shop

Any chance that you used the correct length bolts somewhere else in the plane by mistake?

Any chance that the blind nuts (assuming that that is the mounting system) haven't been pulled all of the way into the wooden base? I had to draw some in with the bolt and a washer..then back everything out and then mount the engine. Rich

I think he is talking about the motor mount to motor connection and not the motor mount/firewall connection

As mentioned above just get longer and keep those somewhere for your next project if you find them too short.

Steven

i have to almost always draw my blind nuts in that way put a few drops of ca glue on them afterwards making sure not to get any in the threads.

The Twist 40 ARF manual calls for using 3mm socket head screws to mount the engine to the mount. The stated length is 20mm or 0.787 inch (just over 3/4"). Then they call for 3 mm washers & nuts. If this is what you have and it isn't working (for whatever reason) then you need longer screws which should be readliy available at the LHS. 8-32 hardware would do just as well if you have it laying around.