Hopefully somebody here can help me with this on going problem that has gone on for a long time with my O.S LA-40 for my Sig kadet LT-40 trainer airplane. What keeps happening is that my engine always sounds good during the run up on the ground, then when I take off, after about 2 minuets, the engine always quits and I have to make a forced landing in a glide. My airplane has been badly damaged because of the engine quitting when my plane was far away and I couldn't bring it back to my landing site. What usually happens is when I go to throttle up in the air, the engine just quits right away. Other times, I can hear the engine running rough all of the sudden then it just craps out. Can't find any apparent reason its doing this. Keep adjusting the mixture till it runs smooth and it seems to work on the ground but like I said, there's nothing more annoying then an engine that runs good until its in flight. The other day, my engine seemed unusually hot after it ran for a few minuets. Hotter than normal anyways. What could be the cause for this? I suspect some friction between the drive hub and the prop but I took apart the engine and found nothing. A lot of times after my engine quits, its hard to get it started again. And when I do run it up on the ground, a lot of times when I increase the throttle, the engine will want to conk out until I quickly reduce the throttle so that it wont. This is a very annoying problem I want to be fixed. I can never have any good flights without my engine giving me problems. I have wasted almost an hour last time I tried to get it started and keep it running. I have tried everything and can't figure what is causing all the engine failures. The engine is almost 3 years old. Do you think its wearing out?