redwoodcstrvr
Member
I have a factory new YIO-320 Lycoming engine installed on my RV-9A with just over 50 hours. My fuel servo is a Precision Airmotive Silver Hawk. During the early hours of Phase One flight testing I noticed that at reduced throttle settings/idle, in the air or on the ground, I would hear routine "popping" sounds from the exhaust. Engine performance was fine at higher throttle settings and full power was as advertised by Lycoming. Adjusting the idle mixture and aggressive leaning seemed to reduce, but not totally eliminate, the instances of popping. Fast forward to yesterday's start and taxi and I found EGT and CHT on #2 cyl were near zero on my EMS. Taxied back to the hangar, shut down, removed the cowling and found by placing my hand on each cyl. valve cover that the #2 cyl. was warm while 1, 3, and 4 were too hot to touch. This indicated to me that the EMS indications for that cyl were correct and that it was not producing power. I completed the first annual inspection in Sep. and compression was 75PSI on all cylinders. Mag timing and spark plugs were checked and tested as well. I believe the problem of low power "popping" is related to the now cold cylinder issue and lies with fuel injection to that cyl. Any ideas on a course of action in trouble shooting the problem would be greatly appreciated.