As Willie states, the CHT really isn't the correct gauge to use for leaning. It's too slow and has too many other players to give a good reflection of mixture. My Tomahawk has neither CHT or EGT. I lean for best power/RPM until I see a slight drop in RPM, then go back in until the RPMs peak. That seems to serve pretty well as the O-235s are known for plug fouling problems and mine typically show very little deposits, the exhaust stacks are always light gray to white, and the cylinders aren't showing any large buildup of junk. However, I have noticed that the sensitivity of carburetors seems to be all over the map, so a procedure that works well in my plane, may not necessarily work well in yours. The carburetors on the O-235 in my Tomahawk and the O-200 in my KR are the same model with a different venturi and but the sensitivity to mixture and throttle settings seems to be significantly different between them. The mixture in my Tomahawk only needs a slight bump with large changes in altitude. The mixture on my KR always needs to be fiddled with for altitude and throttle settings.
Jack's description of the gauge sounds like a single point Alcore EGT gauge, which is there to use for setting the mixture. If that is the case, the star is nothing more than a reference point so your eye knows which line it was looking at on the gauge. Typical setting on that is to find the peak EGT setting with the mixture, then richen 50 degrees F (one bar) rich of peak EGT. -Jeff Scott Los Alamos, NM ---------- Original Message ---------- Hi Jack Are you sure about that? Normaly that is the way the EGT is marked. The Cyliderhead temp will not help for mixture settings. ____________________________________________________________ The difference is clear. Click now for a great laminating machine! http://thirdpartyoffers.juno.com/TGL2141/fc/BLSrjpTG3HvRghp8xViBUAiU30JxhXkWbQm1XANJF6ln9OzLVKnqeKA4TRW/
