Then as mention by Tyler there may be a carbon blockage at the de-compressor port of the cylinder as it is a relative small hole. I have seen this on a couple Husqvarna chainsaws. Later today I see if I can find out the thread size is on the Husqvarna de-compressors as the Chinese probably used the same style setup. I got them in stock just a matter getting them out and checking against my threading tools.
