Remember the Super 24 Powertorque issues with kickback and difficult starting. I thought you were on the wrong track with the decompressor but now I am not do sure.
Well my brother in Eden claims to have solved it completely. He already changed the nozzle on the decompressor to the small one but that made no difference. He changed the whole decompressor to one from a wreck we found at the Eden dump. No sign of kick back now. The spring on the new one seems much stronger as shown by sucking on the tube. It's a pretty grubby decompressor but he left it as it was.
Remember this converted 24 from an FC does have a heavyish engine pulley from a car air conditioner and kickback was never bad. But now there is none.
