RE: dle 20 break in
Steve, I'm a little surprised you have had trouble with the Castrol at rich ratios. I've run it at 32:1 in a DL50, 2 DA50's and 1 DA100 and it ran flawless for me.
+1 on Ralph's post (Antique) about the sealed bearings on the gassers - On a similar note I've got a SuperTigre 90 that I converted to spark/gasoline several years back. It's been running at 16:1 as has my Converted SuperTigre G51 without any bearing trouble at all. The G51 is turning just over 15,000 on the ground. Neither engine has any roughness in the bearings.