Spare Parts inside engine

[BaseDeltaZero]

I found a little spring and a small rod inside my engine. I looked at exploded views online but came up with nothing. Can anyone help me out? BTW this is my first nitro car and I'm learning as I go. I think it is a Savage SS as it has purple shocks. The markings on the side of the engine say .25 Hpi 3.8

 

[Jam Racing 1]

there is a small hole in the crankpin, put a bit of grease on the spring and little pin and insert it into that hole while carefully lining up the backplate onto the engine, that pin and spring are so the pullstart will work and are important to get into place correctly