I have just spent an afternoon experimenting with the new (but broken in on a bench) Saito 100 mounted in the UCD inverted. I have arrived at a few tips to share about this setup.

1 - Starting. I have attached a 90 degree bent piece of pushrod into the needle valve in order to be able to judge exactly how far out the proper setting is in number of turns. I set the position of the bent pushrod pointing directly backward when at this setting. I counted the number of turns from that position to having the needle valve closed completely. I can now open the needle valve from completely closed to the proper setting in just a few seconds. Fuel the plane with the needle valve closed. Advance prop clockwise to the compression cycle so the starter motor can get a head start. Attach the glow driver. (I have a remote one just above the wing) Open throttle to just above idle. Open needle valve to proper setting. Punch it with the starter motor. Starts first time, every time.

2 - Settings. The low speed idle will need some adjustment. This is not because the setting is that far off with the engine being inverted. IMHO, it is because the range for the proper setting of the low speed needle is very narrow in comparison to an upright one. This is how it seemed to me when trying to get a reliable low idle, with good transition. 1/8th turn in any direction other than proper was not nearly as good.

I the tank has any fuel in it at all when the motor stops, and you are near the plane, be sure to close the needle valve.

Also, when setting the low speed idle, and you think you have it good, pick up the tail of the plane so that the fuse is level. You should hear very little (there will be some) change in the idle speed.

Just some Texan experiences with this combination that I thought I would share with y'all.