May or may not be true, they say don't take more than 2 aspirin at once, but I'm nearly 2m tall and 95kilos, so I sometimes take 3. What I'm saying is it may depend on the ARO and the carb in question, manufacturers often make unnecessary statements to protect themselves. My model technics ARO doesn't have such a warning on it, and I don't think the HPI stuff I have does either. Also, I don't see how it can get to my o-rings... I don't stick it in the fuel line or needle tubes, straight down the carb throat. It's how I was taught nearly 15 years ago when I got my first nitro, and I've never questioned it.