I bought a tmaxx used with a drop in os engine already installed on it.. it runs good, seems about the same as the stock engine.. probably a .15 but i can't decide for sure bc os offers so many engines that fit the tmaxx.. i took a few pics, all it says on the right side of the crankcase is cv-r and os on the other side.. os offers a cv-r .15 and .18 and maybe others that are cv-r but these are the only 2 i know about.. anyway, please help id it! it has a broken high speed needle valve so i can't use it til thats fixed, but i don't want to order the wrong part! plus i want to get the sullivan start system for it, but again, i don't know what engine i have..