OK, here is my next "last" post on the subject.
Since my last "last" post, the problem reoccured. It seems that just sitting overnight, fuel didn't leak past the float needle valves enough to cause a flooded probem, but several days worth of sitting did (Frustration!!!) so I called Roger on the 'phone. We talked for 20 minutes or so and I was left with only one possibility of the several he provided; corrosion in the float needle valve orifice. I looked carefully inside with a flashlight and my magnifying head band (and bi-focals) and could see none, but the hole looked kind of rough. Maybe the roughness was caused by a small amount of otherwise invisible ethanol induced corrosion?
There was no bevel of any kind, just a hole in a flat surface. I got a new drill bit, kind of small, and spun it in the hole by hand, slowly, lightly. Now there was a nice shiny beveled ring. AHA! My euphoria only lasted about 12 hours. It leaked worse than before. Turns out the "new" drill bit was too sharp and it caused a bit of "chattering" while being turned, leaving a scalloped bevel. Not good. What to do? I cast about and could come up with no good way to polish this bevel to the correct angle. How about a custom tapered wooden dowel? How about a #2 lead pencil properly tapered? A little file work later and I was spinning that pencil like I was trying to start a fire the Navajo way.
The graphite worked as a polishing compound and after a few minutes on each carb, and resharpening the pencil several times, I had two nice beveled seats for my nice new (replaced last week) float needle valves. After flushing thoroughly I let them sit from Saturday until Monday, with the fuel valves open, and the Rotax fired right up just like it did when new. Only one test to go. I'll wait until next week to start it again, sacrificing flying for testing just to make sure it works. If this doesn't fix my problem there'll be another "last" post.
Thanks Roger for your help.
Alan
