I fly an RV-7A with a carbureted ECI O-360 and fixed pitch prop. On a trip last night, OAT averaged -5F at 4500 feet. EGTs varied from 1290 on the left front cylinder to 1415 on the other 3. Sorry, I can't remember the cylinder numbers as I type this.
After 2 1/2 hours of normal enroute temps and operation, I reduced power to start the descent and the right front cylinder EGT just started to skyrocket. I then went to full carb heat on and the EGT lowered to its previous range. Of course, I enriched the mixture as I descended.
I tried it 2 more times. Each time I closed the carb heat, the right front cylinder EGT started to skyrocket. Each time I select full carb heat on the EGT came down.
The plane, engine/prop combination has a 180 hrs. on it over the past year and a half.
Has anybody seen this before? Any ideas of things to check out?
Thanks, Mike
After 2 1/2 hours of normal enroute temps and operation, I reduced power to start the descent and the right front cylinder EGT just started to skyrocket. I then went to full carb heat on and the EGT lowered to its previous range. Of course, I enriched the mixture as I descended.
I tried it 2 more times. Each time I closed the carb heat, the right front cylinder EGT started to skyrocket. Each time I select full carb heat on the EGT came down.
The plane, engine/prop combination has a 180 hrs. on it over the past year and a half.
Has anybody seen this before? Any ideas of things to check out?
Thanks, Mike