So...decades ago previous owner deactivated a cylinder to use as an air pump to inflate tractor tires.
Now, that lifter is stuck in the up position.
Dead miss and wheezing sound.
I've tried GENTLY tapping it back down, to no avail.
Going to pull the side cover and see if I can rectify the situation.

Last edited by Crowbar65; 06/21/2021 2:02 PM.