RE: What fuel for Norvel .15
I use 10% Nitro and 20% all castor, I think castor works well with their ceramic technology. If you have the RC engine it is very well behaved and it will idle extremely well on the stock carb. The stock carb has a similar bore size as most other .15 engines by the spraybar is much larger, hence the good fuel draw and stable idle. It does limit the high end a little so if you wan't a little more power you can put in another .15 carb (the MVVS .12-.15) is a direct drop-in.