RE: OS 1.08 Nitro engine
"I have never seen an engine harmed when using any brand of store bought fuel."
In all the years of my flying, I have only gotten one batch of bad fuel. Someone, somewhere, had not added the oil to the mix. I spent a considerable amount of time trying to figure out what was wrong with my engine. In desperation, I tried some old fuel I had lying around, and everything was fine. Fortunately, it wouldn't run long enough to cause harm to the engine.
Les