Pressure/Vac Test Sealing?

[WI_Hedgehog]

Pull 15 inches of Mercury, if you pull 7.5 vacuum, that about 3 psi. Too low.

You are right! The MightyVac MV8500 scale is PSI on the pressure side and inHg on the vacuum side--thank you!

Decomps will almost always leak at 7 inches of vacuum. Usually pulling out on them slightly will seal it off.

Thanks for the tip. Pulling on it helped, turning it several rotations seems to have "lapped" the surfaces or at least cleaned it up better than I did (and I got it "clean" from what I saw). It now seals well so I won't use it so it doesn't carbon up (probably doesn't matter much in the big picture).

 

[muddy42]

I have a box of scraps that I use for this - generally pieces of rubber inner tube next to the muffler/cylinder, then a thin piece of metal and finally a block of wood. All with two holes drilled in them to fit the existing bolts. Every saw seems to require a slightly different setup. I sometimes us a sash clamp to hold it all together. I generally send air through the impulse line and submerge the saw under water. Dry the saw off and repeat out of the water for vacuum.