Finally got my Zenith carb adjusted on my 2180 VW to consistently and reliably idle at 700 RPM. I found that the torsion spring between the butterfly shaft and the throttle arm was not strong enough to return the shaft to the full closed position. I added another extra tension spring from the bracket on the shaft to the throttle arm. Playing with the mixture control from the cockpit while the throttle is closed, I can get idle speeds down to 550 RPM. Don't want to be there - the engine still runs, but is about to shake the plane to pieces. 700 RPM is much smoother and the 4 straight Dragon Fly pipes sound great. Still have to be careful to slowly advance the throttle out of idle or the engine will cough once and die. Above 1000 RPM I can snatch and punch the throttle any which way and the response is quick and positive. Yes, I used an electronic tach checker to verify the Grand Rapids tach readout. I am betting that landing roll outs will be much shorter now. Now, on to fixing the high oil temps.
Sid Wood Tri-gear KR-2 N6242 Mechanicsville, MD, USA
