I just got my new Volcano S30 (my first R/C vehicle). The pull start is very difficult to pull. I managed to get it started yesterday to burn my first tank of gas for break in. It was very difficult to pull the starter rope. Occationally it was easy, but mostly very stubern. Tryed to restart to run second tank thru, but not can't pull the rope at all. I tried taking out the glow plug and pulling it, still stuck. Any suggestions? Thanks

I'm no nitro expert,but did you run that first tank super lean and lock up the motor.It should be a little hard to pull when new,you said you took the glow plug out and still couldnt pull it.I would check the pull start assembly,make sure something did not break inside,then i would start checking the motor.

piston is stuck at TDC.

put some ARO in the glow plug hole, heat the engine with a hair dryer for a couple minutes and try again with the glowplug out.

^^agreed. sounds like on the 1st tank you let the motor cool down with the piston at top dead center. not supposed to do that. the pistion to cylinder "pinch" is tightest at TDC. when you let the motor cool down with the piston there, it can get stuck.
use your after run oil applied through the glow plug whole, and use a hair dryer to heat up the motor. that should allow the piston to move again.