Good question; and it may not be fixed.

As you know, I have about had enough of this thing. Your suggestion of the third line, and Dick's talking about the general unsuitability of fuelers, led me to violate the Prime Rule of Troubleshooting; IOW, only change one thing at a time.

I had a sufficient case of the reds to know that if the next attempt failed, I was going to bag the whole thing; so I did FOUR "mods":

1. Yanked the SlimLine fueler and replaced it with a fuel dot

2. Plumbed a third line and made the feed line a straight shot to the pump, per our conversation

3. Fixed the sloppy throttle linkage

4. Used "straight" Cool Power 15%, instead of the extra castor blend that was gumming the engine up in this cold weather

Oh, five mods. I changed to an APC 18x6W prop.

The engine ran great yesterday for six flights It is still hanging lean when going to idle after some minutes at advanced power settings, but I have given up on fixing that and just pay more attention when I'm landing. The excellent handling characteristics of the airplane make that easy to do.

But the last flight, it choked a few times when I applied full power for uplines. I'm hoping it is simply a matter of the extra clunk screwing things up; I'll check that tonight.