one way check valves specs

[walleyehunter13]

Hooked a vaccuum tester up to all my check valves on the oil lines.
It's a 2001 30hp 3cyl 2 stroke mshz.
My bottom w cylinders valves popped at 6.5" hg and held vaccuum at 5" but cyl 1 valve held no vaccuum at all, but also did not allow anything to flow from the reverse side. I'm presuming that top one is defective?
Manual says nothing about the check valves so I'm just scratching my head

[erniefish]

Hooked a vaccuum tester up to all my check valves on the oil lines.
It's a 2001 30hp 3cyl 2 stroke mshz.
My bottom w cylinders valves popped at 6.5" hg and held vaccuum at 5" but cyl 1 valve held no vaccuum at all, but also did not allow anything to flow from the reverse side. I'm presuming that top one is defective?
Manual says nothing about the check valves so I'm just scratching my head

I have a txrc 150, terrible idle , chased my tail through multiple carb rebuilds , ( I am not a full time mechanic) asked my pro fessional friends to rebuild carbs , ( no help ) researched the check valves on the block , multiple failures , replaced all bypass valves perfect fix , they do fail , and I believe sometimes more than one

[walleyehunter13]

I'm going to replace the one that can't hold vaccuum, I got a buddy who ditched his oil system on his 30 and he offered to send it all to me for free so I'll check the valves on his and see if the ones I think are working are the same.

[rodbolt17]

talking about two different valves with different functions.

the OP is discussing the inline oil line check valves.

the other is talking about the puddle drain or recirc check valves that not all Yamaha motors used.