I did run some charcoal lighter without ether today.

Two issues.

A. Castor oil doesn't blend with Walmart brand charcoal lighter that I have. Motor oil should be fine, and synthetic should mix, if you are willing to go that route. I'll try both when I get a chance.

B. It didn't run well. The Magnum .52 four stroke I converted was maxed out in compression. This engine is a bit limited in it's compression adjustment range. My FS-48 is still in pieces after I disassembled it for inspection. I started with about 2.5% Amsoil ACB. I got a couple bursts and that was it. I took out my heat gun and it still wouldn't go. I added ~2% more and could get it to start hot. It ran but was missing and RPM peaked out at half throttle. I think that with a suitable compression ratio things will be better.

Notes.

The exhuast felt very dry even though it was missing. I had white smoke and I think it was the unburnt fuel from the missed cycles. Running was inconsistent because I had to shake the tank occasionally to make sure the castor wasn't settling. I think with a small ether amount this might make a nice fuel. It smells a bit different, but some of that was the cetane booster.

Ugo the MSDS you posted had a substantially different autoignition temp. Much higher than what is listed in charcoal lighter.