Testing Vacuum Advance on Diz

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Mar 28, 2011
Threads
65
Messages
7,346
Location
East Hampton, CT
How the fxxx do I.... so a bit ago I got myself a mity vac and tested a few valves in question on my desmoged 60. One was the vacuum advance on my diz. The outer port (secondary) held vac but the inner port (primary) did not hold.
I sought a new pot and ended up getting a whole diz w/ a pot intact. The buyer told me it checked out. I wasn't clear w/ him how he tested it.
Today I received it and put the mity vac to it. Outer port holds, inner nada. (Photo included).
I'd really like to figure out that putting a vac gauge right to it is not the correct way to verify the diaphragm is intact.

So what say you mudders?

(I'll include the fsm pages that show the method how to officially test it). The reason I stutter over 'how the fxxx do I' is because I've only always had the inner port hooked up straight to the vacuum advance port on my carb and not as it's noted in the fsm.

IMG_5883.webp


IMG_5884.webp


IMG_5882.webp
 
Aren't they all blown at this point?
 
Don't even need a mightyvac, just some emmison hose and suck hard. Oddly all my vac advances work
 
I did test it on mine and the new used one and both primary hold zero vac.
Now I supppse I keep it capped on the carb.
 
Back
Top Bottom