Joe, I actually had a gas compatible valve for the Pitts. The gas valve is red in color from Dubro. The problem as I see it had nothing to do with the chemicals, but more with vibration. The O ring you mention just doesn't seem to be able to handle the vibration and it wears out prematurely. Apparently I'm not the only one that had this occur. I haven't read one example where guys are using successfully in gas engines for this reason. Even DA discourages for the same reason.

I am going to use in glow engines as we have in the UCD, but wnever again in a gasser.