I checked a bunch of motors over the winter, mostly .15's but thought I would group the .09's together to save typing. I told the wife about all the readings but she didn't seem to care, so thought I' post them here. All the motors had a MA 7-4" prop, 10% nitro, no muffler to make things even. YOUCANADDTOIT if you want, just try to keep the same prop brand and size, and fuel with no muffler. It was fairly cold when I did most of these. OK here goes. Cox Tee Dee .09 16,400 rpm control line carb; AP .09, 16,900 rpm; Thunder Tiger GP .10 (had the muffler on because it was in the plane still) 13,500 rpm; OS.10 FP, 17,200 rpm; OS .10 LA 17,500rpm (smaller head shim than stock)