Leave well enough alone and they run very nicely.
That's the point Brett's trying to make, I think.
No, this was just the usual "break it before you run it" approach, discovered at the field, also ending in the usual frustration. I expect it would work fine if you altered the venturi to get the same choke area, but, the point being, *it was already right*, so now we are "fixing the fix".
I have an LA 25 with a "standard" needle that runs very nicely. BUT -- it's an OS needle with a spraybar that's presumably the same diameter as the spraybar for the remote needle. It came to me that way, it works great, it fits in spots that a remote-needle LA 25 wouldn't -- what's to complain about, eh?
The whole thing was pretty innocent and I know no one starts out to try to mess up, but I see it time after time after time, and no amount of warnings, cautions, pedantic lectures, etc, seems to ever make any difference. I have long since lost count of the people who call or write or post about how the 20FP doesn't work worth a darn and then find out that some "upgrades" were made - like an ST needle, "better" muffler, bored-out muffler, added head gaskets, 10-6 Top Flite, etc.
I know the feeling -- I've got a good friend who occasionally flies CL, and I
could not talk him out of putting a Fox combat engine on a Top Flight Score (because hey -- it's a Fox, and they're good stunt engines, right?). We finally got it to sorta kinda work right with half the venturi plugged up with a piece of wood, but it still wasn't nearly as nice a run as you'd get from an LA 46. Now he won't fly CL any more because he doesn't like 4 second laps with a Top Flight score on 60' lines.
I think part of the reason is that it just looks so simple, so the urge to mess around gets irresistible.
I'm actually very likely suffering from the opposite problem -- there are details of my current engine setup that, from reading posts by you and others here, don't sound ideal. But I don't want to mess with it, because it's working well enough for me the way it is. At some point I need to dedicate a month to messing with the power train, and see if I can get more better out of an LA 46 (or at least less slime).