First of all, and most importannt, the engines are supposed to spit out fuel from the muffler it helps keep it cool among other things. you can ruin your engine by not allowing some fuel to cool down the muffler, if you can even get it to run long enough. I'm not too familiar with TT engines, my preference is OS, but see if you can DL a manual from the manufacturers website to get the information for breakin. Most likely, if its an old TT, you run it rich(out with the idle screw) for a tank or two alternating between idle and full power for 8-10 seconds each and let it run mid throttle every few times. If those engines were missing parts, more than likely, unless you put in a new piston and sleeve, it does not need to be broken in because it is already been used. As far as cutoff is concerned, I set my idle when the throttle stick is pulled all the way back and the cutoff when I pull the throttle trim all the way back. You always need an engin cutoff in case of emergency. If I were you I would go out to the field and watch what all the experienced people are doing, and if you ask enough questions and are really interrested in doing this right, someone will "take you under his/her wing" and show you proper setup and safety. That is what happened to me......

Byrdman