Roughrider that is a weird way you have of determining the correct main jet size.
True that! It was only by accident that I got the fracking thing to even start. In frustration, I screwed the idle all the way in to raise the slide, and
only then would it even start at all! Seriously. Having the filter on or off made no noticeable difference. That was how I found out how it ran when bypassing the idle circuit. This was after time after time with a totally flooded engine.
I am thinking now I may have a defective carb. It is SO bad, that I'm just sick to death of playing with it. Really, Jag, if you were here, you'd go, "Hmm. This thing is way, WAY too rich at under 3/4 throttle." So just trust me on that. I'm not a complete idiot.
I'm no guru, but I know the difference between rich and lean. It's not that difficult to determine. I can hear it. I can smell it. I can feel it.
But when you say, "The best jet is the one just
after [italics added.] the one that gave you the best speed," do you mean leaner or richer? I don't go by the numbers; I take my bits and measure the orifice. I notice that different manufacturers use different number systems. Example. In the JNMotor jet kit I got, .89 is a smaller hole than .70. So I just measure. Up? Down? These terms are meaningless. Only actual measurements in mm or inches speak to me.
And just so you know, the carb came with a jet that measured 0.280" and my tests showed a 0.0135" jet made it run OK at WOT. That's how far off the carb was when I started.