---------------------------------------------------------- M14PEngines-List Digest Archive --- Total Messages Posted Sat 07/08/23: 1 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:41 PM - CHT (Snazpappy) ________________________________ Message 1 _____________________________________ Time: 06:41:25 PM PST US Subject: M14PEngines-List: CHT From: "Snazpappy" I have a Yak 52 TW. The CHT in the back cockpit is mostly inop indicating zero. After engine startup I noticed the CHT in the rear cockpit would indicate normally up through about 200 degrees then the gauge would appear to fail and indicate bottom of the scale. I did a little troubleshooting today and put both CHT probes in my dewalt heat gun which can be set in 50 degree increments. Both gauges read normal up to about 200 degrees F. When the heat was increased beyond 200 degrees, the rear gauge appeared to fail and the front gauge read normally. I decided to isolate the rear CHT probe so I put just one probe in the heat gun to find which was the rear and found the rear gauge continued working when it was isolated but would read 50-100 degrees lower then the set heat, when set above 200 degrees, but the gauge continued to function. I then tried to put the front probe back in the gun, with the rear probe and as soon as I put the two probes together the rear gauge again appeared to fail. Both CHT thermocouple are pancaked together and put on the same spark plug on the back of the engine. I have decided for now to replace both thermocouples to see if this fixes the problem, not sure what the problem may be, and was wondering if anyone has any ideas why my gauges are acting this way. I checked the wiring diagram and both thermocouples are totally isolated from each other other than be pancaked on the same plug. Both thermocouple s wiring are running through their own protective sleeves. Any ideas or suggestions are appreciated. Thanks Todd Read this topic online here: http://forums.matronics.com/viewtopic.php?p=511077#511077 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message m14pengines-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/M14PEngines-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/m14pengines-list Browse Digests http://www.matronics.com/digest/m14pengines-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.