No I haven't. But, many years ago, I did convert a OS 120 to burn gas with a C@H ign. and home made syncro spark and ran into a bunch of problems. First of all, regarding those big cooling fins on gassers. They need them, the OS ran HOT. Next you can not get a good fine tune on the needle valves. They do not have fine enough adjustments for gas. I finally put a 91 sized carb on and it improved some. When you are running gas you have a lot less fluid (fuel) going through the engine=more heat build-up, less lubrication. That messy oil coming out the Saitos exhaust is carrying a lot of heat with it. You must increase you oil content a lot. I found I needed 30% oil, (messy) and not even sure that was enough. And of course you will lose a lot of power by switching to gas in the Saito. However, I did find that by putting the 120 carb back on and running in on regular 15% glow fuel, with the C@H ign. and syncro spark it was a REAL sweet running rig. It would idle like no other 4 stroke I have ever heard. Kind-of defeated the purpose though.
It was a fun and interesting experience
Ron