RE: Tower Hobby .75 engine
can't say i love that engine. but hey, i'm the odd man out. had the 75 on my zen 50 and just didn't do it for me. running inverted, it was a pain to start and flights often ended with a dead stick. although i confess i'm no engine guru, i think i'm okay. i've run everything included the infamous YS and nothing, not even the local pro at the field, could get this motor running good. i still have it. maybe one day i'll use it again but for the time being i just don't have the time and energy to deal with it. slap on an O.S. and go. i've nothing but the best experiences with O.S. having owned these: 32SX, 46FX, FS-30, FS-52, FS-60, FS-91, FS-120, FS-160T. each one was a joy to own and operate.