the prop was a 12x4.it was all the hobby store had at the time.he said they would work.the last 12x4 is working ok i guess but later did reserch and found out its not the correct size to use according to this prop graph http://home.merlin.mb.ca/~kmartel/propcht.htm but anyway im working on the last prop out of 3 of those i bought.anyway i finally got the eng tuned some what today and had 3 flights.1 resulting in dead stick to eng failare.took 3 hrs to tune her lol.the only way she would run at close to her peak is if the high speed was very lean and the low speed needle vale somewhat lean allso.that the only way i could get her to run without sputtering .by the way the broke antanna on my transmitter is ok.did range test at 1 mile before flying today.had some great landings today with no wind.very easy with no wind to land.so thinks guys on all ur imputs.i would have never made it this far without u guys.