ORIGINAL: lnewqban
ORIGINAL: gaRCfield
For the past year I've been adjusting my idle mixture based on transition from idle as per manufacturers instructions and what I've read on this forum. I recently had to learn how to work an air bleed adjustment on my YS, and the directions for that were to tune the mixture to maintain a steady idle RPM over a period of 15 to 20 seconds, and not based on transition or a fuel line pinch.
gaRCfield:
Could you explain this a little better for me?
Sorry, but I see no difference between what you were doing before and now, other than switching from idle needle to air bleed.
CGRetired:
For some reason, many members are not aware of the engine forums.
May be showing a link within RC Airplanes forums would help?
There are also very interesting forums about full scale airplanes, batteries, radio systems, unusual models and video and photograph here in RCU.
Before I was adjusting my low end based on transition from idle to WOT, and by pinching the line and noticing the reaction at idle. I am now setting the throttle to idle with a tachometer and watching the change, if any, in RPM only at idle setting.If you drop to idle and the RPM slowly starts to increase, you mixture is lean. If it decreases, the mixture is rich.There are different styles of carburetors, but they are accomplishing the same thing - adjusting the fuel and air mixture going to the engine. Both are turned to make the adjustment leaner or fatter, regardless of what direction you must turn each individual one.Again, I posted this because the methods explained in the manuals, i.e. basing the judgement off transition and pinching the fuel line is very subjective - what might sound like a good transition to one may sound boggy to another. Using a tach and watching RPM at idle is objective - look at the numbers and see what they say. Of course with time you can learn to hear the difference, but it's so slight that a beginners ear may not hear the engine slowing down.