Brand new to this forum and need some help. Need to remove the piston from the end of the crank shaft in a Stihl BR 400 blower, but can't see how to do this. It seems to be held on by a pressure fit ring thru the centre....is this correct, and if so do I need a special tool to remove this ring?
It will have 2 spring clips (one on each end) on both ends of the wristpin. You will see a little indent around the end that should let you get a pick or very small screwdriver under the spring clip to pop it out. Once the clip is out press or drive the wrist pin out from the other side of the piston. Make sure you support the piston while getting the wristpin out as not to damage the piston or the connecting rod. It should come out fairly easy, it is not a pressed fit just tight tolerances. One more thing, on that blower the engine block assy I believe needs to be pulled off from the back of the blower to even get to the other side of the piston to remove the wrist pin.