I know this is a little off topic but my 26 seems to run best between .022 and .024. (by runs best, I mean transitions and runs smoother. I do NOT get more rpm's out of either engine with the gap set wider) It starts the same at .018 as it does at .024 but my DL50 definitely runs better gapped between .022 and .024 with the side electrode cut off some and shaped to a slight point. The plug mod has been documented in other threads here on RCU. I haven't tried the plug mod on the 26 yet.