@Grumpy, my similar mower (victa commmando 2-stroke) is also hard to start, while i pull the cord i'm hearing this loud air sound from the decompressor. Could my problem be the decompressor?

Because i took the decompressor out, the valve lack springiness, seem the diaphragm inside is worn or something.

Under what condition do you need to replace the decompressor?
Btw i have the sealed decompressor and short thread.

Maybe i should also checked whether it start with a tea spoon of fuel because it does have spark.

Am i in the right place or do i need to start a new topic?