I am not a OS guy for R/C cars, but have tuned a few, and they are not finicky as some other brands out there, but then again there really is no engine to finicky for me to tune,"not tootin my horn" It is just that I have been tuning nitro engines since I was 8 yrs old, " grew up flying with my dad" I have tuned sport, some 4 cycle "different animal altogether" and racing, pylon engines for years. Case in point, if anybody knows K&B engines #4011 in particular was a pain to tune no matter what carb you used. I could make that joker scream! if you gave me a little time to learn "that " engine as they all ran a little different. I have tuned a few for guys that were racing for years and could not get the thing to run just right. It is kinda like a piano tuner, or tuning a guitar, it takes an "ear" for it. FORGET temps, take your time and let the adjustment settle in, listen to it, fell it, be patient, it will talk to you just listen. There is NO sweeter sound then a perfectly tuned nitro engine,"to me" my wife and neighbors do not feel the same!
lol. Car engines take a little more patience as the load on the engine varies alot more, BUT the principal is the same. The sound should be a high pitch, smooth, consistent tone at all ranges of the rpm. Sorry this was so long. Happy motorin guys. The engines today are waaayyyy easier to tune then they were 25+ years ago.