Originally Posted by 1967brutus

A fairly decent indication on whether the engine can run properly on its original not modified carb, is to lean the engine to its most optimal setting, and check (with a piece of cloth or filterpaper behind the exhaust) how "dirty" the exhaust residue is. For this you need a stable setting and test after at least 30 seconds of running at that constant RPM.

Then reduce the throttle to wherever you think mixture is worst, leave the engine running for a short while at that setting. Check the exhaust residue again, and check for differences in sootiness of the residue,
Then at that same throttle setting, check how far you can close the main needle and whether running improves.
That will give a rough indication of behaviour in the air.

But I am not very optimistic...

OS max 46 FXi, on gasoline 5:1 mix, no further modifications

felt pretty good on the ground, but turned out to be barely flyable in the air.