Thanks for the answer. I'm retired and completely forgot that it was the weekend when I started the thread. I started the thread when I'd finally run out of things to try and didn't notice it was Saturday.

I mentioned the factory setting really just for info. I figured the factory suggestion of 2.5 turns must have meant that this engine's run setting of 3/4 of a turn might mean something to someone familiar with that engine. That's a heck of a difference. And once I got the hang of it, the engine was no problem to start. The technique suggested in the manual that came with the engine works great. And that's great because when it's cowled, it'll be really difficult to choke or prime as you suggest. Starting it now isn't a big deal, it is the way it runs that is the problem.

I was not expecting that as the advertising says the design is similar to the 46AX so I expected it to break in like all the 46AXs I've bought or set for others. The manual that came with the engine describes almost exactly the same process as I've used with the 46AXs, and says after two tanks of that process to fly the engine rich and expect on each of the next 10 flights to go one click leaner each flight. Since this engine has way more than two tanks through it and it's needle settings from blubbery-rich to so-lean-it-stops cover only about 1/4 turn or about 6 clicks, I figured there might be something wrong with this engine. It's gotten enough runs on the ground to have "come in". And has probably had 10 flights and it's not changed one bit. It's got about 5-6 clicks adjustment. And they're right where they were on about the 3-4 run.

Set it lean enough that it runs smoothly in flight and it'll stop in flight. Set it any other of the 4-5 clicks left and it runs rough.

BTW, I didn't mess with the airbleed at all until I'd established the needle position. The reason is that the engine wouldn't idle at all below 3/4 throttle for a long time. I never had a chance to try and tune the throttle transition because it wouldn't throttle down in the first place. I guess it had 6 or 7 runs on it until it would actually throttle below half throttle. And it was a day later that I discovered that it would keep running at idle. Whatever the time line..... It really wasn't until I risked flying the new Cub that I started trying to tune the airbleed for throttle up, because I didn't want to risk that new airplane. A stumbling on throttle up wasn't what I wanted. Whatever the time line.... Last time I ran it, the idlescrew didn't do a thing. And I didn't start out messing with it at all.

But now that it's gone bad, it's time to send it in. Thanks for your interest.