DA50 goes rich inverted


Active Member
I sure would appreciate some help on this odd and repeatable issue. I THINK it's going rich, but maybe it's just cutting out, not sure.

3DHS 79" Slick
OS 60cc pitts muffler
Redline 45:1
New plug
Engine runs and starts perfectly
Engine has 150 flights
Engine runs inverted at 50% or more power no problem

While doing inverted figure 8's at 30% power the engine will start to miss (sounds like going rich), issue gets worse then I cannot finish one figure 8 before the engine sounds like it is going dead stick. Solution is to throttle up and go back to canopy up. Twice I though I had killed the engine.

Checked clunk, it moves fine.
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The Mistress of Biplanes
Lifetime Supporter
Did this engine used to work ok with no problem on this exact same plane?
How about a new carb kit?


Gold Member
That would be my question too. First thought is air turbulence inside the cowl messing with the diaphragm altering pumping pressure. I once had a similar issue in a cap 21 when going to knife edge. The answer was to run a piece of fuel line attached to the carb breather into the fuselage.

The only other thing I can think of would be the ignition pickup. I know it sounds odd, but once we had a bad one that would only run upside down!
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