Ive had one for a while now. The only problem Ive had is the mufler coming loose. The holes not drilled correctly and the CDI failed not sure what caused it But the engine did get hot on this one run after being cowled fitted a Rexel and have had no problems...Ive just re kitted the carby as the engine had been sitting for 6 months and I wnated to be sure.. Its in a H9 1/4 cub now. It was in a SPAD bi-plane.