The Cessna 120-140 Association Forum

Was looking through the parts diagram and noticed this spacer show #24 (PN:0450195) I have never seen this spacer in any other airplane that uses the conical type engine mount rubbers 85 or 65. I do not have them installed on my aircraft. Anyone know why they are there or have seen them. (I’m trying to chase down a vibration that occurs when I transition between 15-2000 rpm and thinking this could possibly help)

(This was happening before I rebuilt my engine now it’s doing the same thing I’ve tried a different prop and same thing)

Any help is appreciated

Search the forum for that part number. There's been a lot of discussion over the years. (Not a lot of resolution, though...)

My C120 had the metal spacers and I put them back when I change the conical rubbers in May. A C140 also had them. The Cub whose mounts were changed last week did not have the spacers for what it's worth. I believe, though as John notes there are many opinions, that Cessna specified and used the spacers, but Continental/Piper did not.

Oh, I'll bet you dollars to donuts they won't help with your vibration.

Look for something rigidly mounted to the engine that's touching something rigidly attached to the fuselage, like a tail pipe touching the cowl.

What carb do you have? Some people have reported rough running in the 15-2000rpm range with the MS carb and one piece venturi.

Have you tried adding carb heat to see if that has any affect?
Josh

8413 wrote: ↑Mon Dec 18, 2023 8:04 pm What carb do you have? Some people have reported rough running in the 15-2000rpm range with the MS carb and one piece venturi.

Have you tried adding carb heat to see if that has any affect?
Josh

Your most likely suspect.........