The Cessna 120-140 Association Forum

Back-story for context: My C-85 engine continually drains oil from the carburetor inlet during operation. Blows back on the firewall and down the belly. The rumored cause of this is either: (A) worn inlet valve guides, or (B) running a rocker arm on the inlet valve that does not have the plugged oil drilling. (I'm hoping for (B).)

I purchased a set of plugged rocker arms. Sent them off to Lycon to be overhauled. Now I intend to install them in the hopes that this addresses the oil leak. Continental specs are to check valve clearance with the lifter deflated. Which is the source of my question:

How do I deflate the lifter without removing it from the engine? What's the cheat-code? Thanks in advance!
-dave sprinkle

Turn the engine to where the valve in question is fully open. Go have a beer. Works best with warm engine oil (and cold beer.)

6643 wrote: ↑Wed May 28, 2025 2:15 pm Turn the engine to where the valve in question is fully open. Go have a beer. Works best with warm engine oil (and cold beer.)

John, great advice! Thank you!