If I were you, before doing anything, I would read the manual cover to cover, then read it again. Follow the manufacturers instructions for break in. The idling a tank is old school, and works for some, but I prefer the heat cycle method. When an engine is being broken in it needs the rpms to vary and the temps to be in the 205-210 range for the piston and sleeve to be properly broken in. Idling the mill does not do either of these, and causes the engine to load up with fuel. But if you are still fairly new to nitro break in, I strongly recommend following the manufacturers instuctions.