Hartmut, Can you please say some more about this? Especially about the "partial" part? &/or go ahead and post diagrams to be clearer?
My 1946 415-C has a Stromberg carb, but no separate or independent mixture control. What I have learned so far from what has been said on this list in the past, and a little research, is that the Stromberg carb automatically adjusts the mixture -- and is reliable at least up to 5000' MSL. I've been advised by Ed to get a mixture control knob added (ok, maybe at next annual; for now, I'm really enjoying the simplicity, and the plane seems to run fine at every altitude, so count me dumb & happy...and reluctant to mess with something that is working). The engine is a C-85. My normal economy-cruise is 2150-2250 RPM (red- line on mine is 2575). Is that "partial" enough to get the Stromberg to be working, in your view? And what the relationship is between amount of throttle & efficacy of the Stromberg carb is not clear to me. It also wasn't mentioned in any of the Stromberg articles I could find online... so I'm unfamiliar with the notion, and would appreciate more explanation. Thanks - Linda 3437H (Sky Sprite) '46 415-C L.A. Hartmut wrote: While I was playing around with the control, it came to my mind that it might not be emphasized enough that the mixture control on Stromberg works ONLY when you have throttled back a bit, like 3/4 th of the full range. The Stromberg will not show signs of leaning at full throttle or at idle. It is important to remember that. At full throttle, the leaning effect is maybe there but I can not feel any roughness, regardless how far I pull the control. At idle there is no effect either, since the throttle is closed and no low pressure can be used for creating the leaner mixture - the low pressure port of the leaning mechanism lies below the throttle flap. Ok this is hard to understand without seeing at least a diagram. To say it simple, Strombergs can only be leaned at a partial throttle setting and one should put that into consideration.
