Chainsaw Repair

First I had to look up 'impulse hose', my old 036 repair manual just calls it 'intake hose', perhaps impulse is a later term? Anyway, the one on it was only a couple years old but did indeed have a pin hole, alas, replacing it still made no difference.
Have also checked boot to engine and tank vent.
It would seem to me to be a useful diagnostic that while it's revving in partial choke mode, I can open 2 turns or completely close both high and low jets and neither affects the rpm's. But What it indicates is over my pay scale,
thanks!