Both my flying partner and I are using the DA 100 and see a similar
characteristic but not to that extent. After I get it warmed up a bit and
get the idle set using the trim it is always too high when landing but I only
have to drop it a click or maybe two at the most to get it down. On most
of I my engines I can set the low needle so that I can let the engine idle
for several minutes and they will still accelerate very clean. My DA does not
seem to like this. After the warmup and taxi out, which is a short period, the
engine is a little rough (rich) when I bring up the power for takeoff. It never
does this while flying so no big deal. My suggestion would be to try
richening up the bottom a little and see if that doesn't help. I prefer not to
do this but it's such a great engine this is a very minor issue. Mine has never
quit on landing so I'll live with it. Hope this helps.