Chris,

I also have an LT 40 and my 40 LA fit with the motor mount in the kit, it was out toward the end of the mount but I felt it would be fine. My thought is maybe they put a mount from the LT 25 in with your kit by mistake. Go to www.sigmfg.com and go to contact us,and give them a call and they will be more than willing to help. I've contacted Sig 2 times with minor problems and questions and both times they have been eager to help. I've got over 60 flights on my LT 40 without a problem, its a great plane. I'm almost finished with my somethin extra hope its as good or better.

P.S. I strongly suggest using their #64 rubber bands. If you can't find them at your local hobby shop, you can get them directly from sig.