also, try putting on a second washer on the glow plug and running it a bit. Also, set the tank level with the carb because what can happen is fuel is being forced into the carb by backpressure and gravity, basically flooding the engine. when you turn the prop backwards it spits out the fuel because there is way too much inside. If it is really hard to bring the piston back down from tdc rotating it in the normal opperating direction, that again points to too much fuel. Two strokes have a fuel system where when the piston is moving up, it draws fuel in through the carb. when it reaches tdc, the intake closes, meaning that on the downstroke, it is compressing the fuel air mixture, so that when the piston reaches bottom, the exhaust can only go one way because of the force of the fresh mixture coming in.