abufletcher

A got the new carb unit for my RCV91cd and took the model out to the field for some tune-ups and test flights. I've been told (by the people at RCV) that the factory setting for the low-speed screw (in the center of the throttle arm) is fine. But to get a smooth idle (very smooth at about 2400rpm) I had to turn this screw (clockwise) about a full turn in 1/4 turn steps. But while this solved the idle problem, the engine seemed to be running lean at the full-throttle setting, even though I was only getting around 8500 (less than the 9000 I've had in the past).

So my real question is this: What is the low speed screw actually doing? I'm assuming it adjusts the gap in the spray bar, but don't know in what way. And would making this adjustment have the effect of leaning out the engine at the top end? Normally the RCV91cd puts out a LOT of oil during a healthy run. But today it was running hot and with little oil even with the needle valve opened out about 2-3 turns (which is usually a LOT for this engine). I did two flights. After the first the engine was hot...and hot for quite a while. I opened up the needle valve a bit for the second flight and heat wasn't as much of an issue, but I wasn't getting as power from the engine either. It's not bad, but also not ideal. I'm glad I'm learning the ins and outs of this engine before putting it in my Albatos C1.

Anyone have any ideas or suggestions?