Good answer bigted, I am pretty confident the decompression valve does what it's meant to. I never pondered whether it pulses out just stays shut but it makes sense since the piston is moving very rapidly even at idle and every up stroke is a compression stroke. The PT certainly lives up to it's name. It rolls it's eyes and tells you "is that the best you can do" when it tackles 2 foot grass.

Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!