OK, I can probably look up location of governor port, dunno if I have a gauge that goes that high, will look.
Got the VB out and apart, small kine sludge, but the "shuttle valve" behind the spring loaded TV was sticky at first, sprayed out with penetrant and is free as can be now.There was in one passage some thick goo, maybe a gram or so, but maybe that was a dead end passage?Consistency of peanut butter and gray/black.
Got an accumulator spring out of a parts loadflite, and will install in my 904 as per JohnRR's kind advice.
I still am at a loss to explain why it came on so sudden, all I can think is it didn't like sitting for 4 months and some sludgy stuff set up either in the VB or the governor assy.
Will try to air test clutch pack before I install VB.