He verified this by doing the above linked test which showed no crankcase vacuum at idle.
Crankcase vacuum tester.
Always gently rotate the crank in each direction to disturb the seal lips and verify that they hold under vacuum.
After my local mechanic did a smoke test and checked the vacuum lines he suggested that the issue might be the pcv valve in the cover.
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Vacuum pressure testers cam correct crankcase vacuum pressure tester.
Next pull a vacuum on the crankcase and see if that holds.
There is some argument about whether to do vac first and pressure second or pressure first and vac second.
The morning i went out to replace the pcv.