When the engine is COLD and the mags are OFF, (ABSOLUTELY DOUBLE-CHECKED COLD AND OFF)
You can, then, gently pull the prop through 4 cycles and feel how well defined each is. If you find a mushy compression or two, compared to the others, I am told that may give a good hint as to where to start looking for power loss. BUT, DO NOT GET CAUGHT BY A KICKING PROP! Very respectfully, Dave Winters -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Hartmut Beil Sent: Tuesday, March 31, 2009 12:08 PM To: [email protected]; Techlist Ercoupe Subject: RE: [ercoupe-tech] RPM at takeoff and cruise altitude John. He doesn't have to check his Tach. With a climb performance of less than 500ft behind a C-90 barely reaching 3500 ft - That is NOT a tach problem. This is lack of power. There are at lest 10-20 horses missing. And I am afraid adjusting ignition alone will not remedy that. What strikes me is the reference to a radial engine. While I never flew behind one, I saw many firing up and that was usually a show of uneven power . Maybe the C-90 is running rough? But with that much loss of power as described I would make sure that you are having the right parts attached to the engine . That is clean air filter, working carb heat, correct carburetor, correct intake spider, no leaks in the intake system. Correct timing, free exhaust and the correct pitched propeller. Hartmut _____ To: [email protected] From: [email protected] Date: Tue, 31 Mar 2009 10:25:38 -0400 Subject: RE: [ercoupe-tech] RPM at takeoff and cruise altitude Alan: First thing to do is have your tach checked. They are notoriously inaccurate. Second, confirm that the engine and prop combination can make the required static RPM (2250-2375 according to Ed's post). If it cannot, it is unairworthy and you need to figure out why. The two likely causes are incorrect prop and low power output. John Cooper Skyport Services www.skyportservices.net _____ HotmailR is up to 70% faster. Now good news travels really fast. Find out more. <http://windowslive.com/online/hotmail?ocid=TXT_TAGLM_WL_HM_70faster_032009>
