Gero Adrian Heliman Location: Stuttgart, Germany
| Hello squirrel,
maybe you should change your needle in the carb, for the various type of fuel. Default is the 2°, runs great for typical 5% CP, for the 0% with less oil you should increase to 1,50° - if you want to use e.g. a 12 % CP a 2,5° works better.
I've tested a lot with several needles, Jan's standard (0% Nitro) works great with the 10mm Lotterle - I prefer the 11mm one with the 2mm needle and a fuel with 5% Nitro plus 12% - smooth running, but the Webra is (for me) the better one. Problem - availability 
Best regards
Gero |