Hi Noobee, One thing to remember is that more nitro doesnt always create more power, it is just there to help with combustion (Read the fuels thread). If you have too much nitro, it can cause detonation, which will hinder performance, what you could try is a colder plug, and a shim, or go back you your 16%. This will also keep the motor cooler and les chance of detonation. Just remember to go easy on the motor when to change fuels for the first few tanks, DO NOT RUN IT HARD as soon as you change the fuel, remember that the engine needs to 'settle' with the new fuel first, you should do this even if you change fuel brands. Please let us know how it goes.