Originally Posted by
Glowgeek
Curve with no jet reduction
Curve with smallest jet
I'm thrown a bit by the results. I thought the reduced jet size would have needed
less leaning just above idle.
Eductor effects can be unpredictable, perhaps. I am baffled by that result as well.
These things are weird anyway: I can give you this example: in an older airbleed style carb where the NVA basically consists of a needle valve, an orifice and a straight pipe into the venturi throat, leaning the engine to the max on the needle alone (solenoid deactivated) one would think that there is no "headroom" for the solenoid to control mixture. The weird thing is that the "chopping" action of the solenoid promotes evaporation and at around 90~95% solenoid opening (where the chatter of the valve becomes audible) the engine goes rich on less fuel than the "leanest possible" straight through needle setting...
I cannot fully explain what you see here, but at times weird stuff happens...