SixPapaCharlie
May the force be with you
- Joined
- Aug 8, 2013
- Messages
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Sixer
Flew to breakfast with my family which was maybe a 10 minute flight.
I flew them back to home base and then I flew up to another field to give a pilot friend and his son a ride.
We fly for maybe 40 minutes.
I show him the lean assist feature and notice that as I am leaning, the engine starts acting too lean long before 1st peak.
I say hmmm, that is odd but nothing really seems amiss.
We make our way back flying a bit richer than I normally would.
Drop him off and I prepare to head home.
On my takeoff roll, everything is normal. Rotate and half a minute later, I begin to dial the mixture down to the green arc. SOP.
Well no exaggeration, I barely moved the mixture and the engine starts shaking. Quick undo what you last did!
Engine seems fine, Vx, do a 180 and get back
Over and over on DW leg, nudging the mixture down and the plane shakes. Still well above normal cruise mixture.
Land, Call my CFI and says not being there it is difficult, there are several options.
He has me do:
1. normal run up: No issue
2. High RPM run-up. Left Mag, and intermittent popping
I have had the plug issue before where you burn off the carbon and this seemed different. It was a lot of random popping. Not at a consistent cadence.
I do the burn off procedure and try again same result with the popping.
CFI suggests trying alt air, no fix there.
Suggests possible induction ice which I haven't googled yet.
I go through about 3 more iterations of the mag check at 1800, then again at 2400, then do the burn off procedure.
I do a full throttle run down the runway and there is no issue
I do it again, reducing the mixture and no issue.
One more low and High RPM mag check, and the popping is gone.
Parking brake, full throttle, start reducing mixture and it is dead smooth.
Had a long talk w/ CFI and we decided to do a couple more high rpm mag checks and if the popping is gone and everything is smooth, then do a lap around the pattern.
I go for it and the plane runs as perfect as ever. I circle up to 7000 and then make the 15 minute flight home without issue.
Could a dirty plug cause the engine to shake when reducing the mixture? And I mean a touch like from 26GPH to 20GPH whereas I normally fly at 14GPH so still way more fuel than normal but a hair back from full.
Sorry this is so long.
I flew them back to home base and then I flew up to another field to give a pilot friend and his son a ride.
We fly for maybe 40 minutes.
I show him the lean assist feature and notice that as I am leaning, the engine starts acting too lean long before 1st peak.
I say hmmm, that is odd but nothing really seems amiss.
We make our way back flying a bit richer than I normally would.
Drop him off and I prepare to head home.
On my takeoff roll, everything is normal. Rotate and half a minute later, I begin to dial the mixture down to the green arc. SOP.
Well no exaggeration, I barely moved the mixture and the engine starts shaking. Quick undo what you last did!
Engine seems fine, Vx, do a 180 and get back
Over and over on DW leg, nudging the mixture down and the plane shakes. Still well above normal cruise mixture.
Land, Call my CFI and says not being there it is difficult, there are several options.
He has me do:
1. normal run up: No issue
2. High RPM run-up. Left Mag, and intermittent popping
I have had the plug issue before where you burn off the carbon and this seemed different. It was a lot of random popping. Not at a consistent cadence.
I do the burn off procedure and try again same result with the popping.
CFI suggests trying alt air, no fix there.
Suggests possible induction ice which I haven't googled yet.
I go through about 3 more iterations of the mag check at 1800, then again at 2400, then do the burn off procedure.
I do a full throttle run down the runway and there is no issue
I do it again, reducing the mixture and no issue.
One more low and High RPM mag check, and the popping is gone.
Parking brake, full throttle, start reducing mixture and it is dead smooth.
Had a long talk w/ CFI and we decided to do a couple more high rpm mag checks and if the popping is gone and everything is smooth, then do a lap around the pattern.
I go for it and the plane runs as perfect as ever. I circle up to 7000 and then make the 15 minute flight home without issue.
Could a dirty plug cause the engine to shake when reducing the mixture? And I mean a touch like from 26GPH to 20GPH whereas I normally fly at 14GPH so still way more fuel than normal but a hair back from full.
Sorry this is so long.
I thought you meant after takeoff/climb.. I like to keep it rich for climb to keep the CHT's down. We can lean to a cruise climb at 17gph, but that just throws oil on the belly and the CHT's climb fast.
