Q: I have a factory reman Lycoming O-540 E4B5 with 300 hours and 2.5 years on it. At idle (1,000 rpm), my JPI is showing alarms on the #1 EGT for having a large differential — #1 EGT is only 600° while the rest are 1,200-1,300°. Above 1,500 rpm and higher everything seems fine with normal readings and maybe #1 CHT a little lower, but I expect that since it is first in the airstream. I have full data printouts from the JPI.
I have checked the plugs even though my mag checks are fine and replaced the probe on #1 EGT with no change. I’m scared to think I have stuck valves. [Read more…]