Marvel Mystery oil is not some kind of magic cure. It has been around for over 50 years and there are many other upper cylinder lubricants that do the same thing. And they work. Last April I tried starting a compressor and flooded it. It sat until a couple of weeks ago, and the intake valve was stuck so tight the engine would only turn 1 3/4 rounds either way. I put in Marvel and tried it every day and I think it was the 5th day or so, it turned over like a new one. I have done this to many engines, and I'm sure the guys on this forum who have been working on engines for 50 years have done the same thing. I would not have the patience to put things back together if I took more apart than needed. It may be something else, but I sure wouldn't take things apart before I eliminated the simple things. Marvel mystery oil will also dissolve carbon in your ring groves and help your engine with better compression and oil control.
