Joe Horton wrote: > With an hour in the air this evening I was playing around with mixture > settings. I discovered that (at least with my engine set up) that there > is a real sweet spot in the mixture setting on the aerocarb. The biggest > signal that I got when I found it was how much smoother the engine got. > The noise (read vibration) that has been bothering me for months was > turned into this beautiful hum.
One of the many things I've learned now that my KR is flying is that during cold weather, the RPM range where the mixture is good enough that the engine runs smoothly is much smaller than over the summer months. This is presumably because the fuel doesn't mix with air as well on the trip through the manifold as it would during warmer months. And yes, carb heat improves things to an extent. After I flush out my fuel system tomorrow, I'm going to remove my ram air snorkel and let the carb get it's intake air from inside the cowling (it'll still be filtered) for the rest of the winter. My under cowling temps were only 65 degrees yesterday, with an OAT of 40F or so, so I think that'll work fine. Ram air only gets me about .2 inches of manifold pressure with my airbox the way it is, so I think it'll be an improvement in the quality of the mixture. I'll reinstall the snorkel for Spring use. It only takes a few seconds to swap it out. The mixture gauge is a huge asset in keeping the mixture in the right place. Without it, I'd always be guessing as to whether I'm too rich or too lean... Mark Langford, Harvest, AL see homebuilt airplane at http://www.N56ML.com email to N56ML "at" hiwaay.net