Help in Advance

[Road Warrior 808]

I need a little help with a Vacuum Advance problem. I'm 99% sure mine is faulty, but I want to be absolutely certain.
I have a stock 1975 FJ40. It has the single diaphram advance only. I don't have a proper vacuum advance tester, but applying "manual oral suction" yields poor results: ie the plunger doesn't move and there is no vacuum created.
Advice? These can't be bought at Lordco, etc, so I wanna be sure before I search one out.

 

[UCruiser]

Yeah I wouldn't be drawing too many conclusions based on "manual oral suction"... I've used the hand pumps on brake bleeding kits as a vacuum source in similar situations in the past... Can you feel vacuum on the supply hose as you rev the engine? Most advances won't kick in until you reach a predetermined minimum RPM...

 

[Road Warrior 808]

The Lord Humongous..... my former nemesis. I appreciate the irony.
Anyhow, suction (vacuum) is present from the rubber line at the vacuum advance end.
I borrowed a suction tool from my neighbor and the main shaft moved maybe 3/32" before it seemed to encounter a stoppage.