How often do you guys remove, inspect, clean and re-gap your spark plugs?
Only at annual or more often?
Every service, absolutely.
I thought so.
The MM for the Cirrus for example calls that only at annual / 100hrs.
So my SC doesn’t do it at the 50hrs inspection (unless I report a problem, obviously).
It depends on your attitude to risk.
Fine wire plugs don’t seem to wear. Setting aside the crappy Champion resistors (which seem to last barely a few hundred hours), I would expect these plugs (I use Tempest) to last 2000hrs with barely any visible wear.
So one is really checking for other defects, like cracked or broken insulators. I recall reading a long thread on a US forum, probably Beech, where there were many reports of cracked insulators, on the type of plug which had the longer reach and was used in a turbo engine. I think you will be familiar with some Cirrus directive regarding this, following many cases of insulator cracks. Both Beech and Cirrus use the Conti TIO550 engines. My feeling is that it may be the combination of the engine and the longer reach which may be the cause.
Also one needs to remove both plugs to properly visually check the exhaust valve portion of the cylinder head for cracks. These cracks often start near, or even at, the plug hole.
I don’t know why Cirrus don’t do the plugs more often. It is the easiest job there is. OTOH if you drop a plug, it has to be binned. If somebody drops a plug and puts it back in the pile, the whole pile has to be binned because you don’t know for sure which of the 12 got dropped
http://www.eaavideo.org/video.aspx?v=1826468805001
Cheers VicThere are several horror stories amongst Cirrus owners posted on COPA associated with Champion plugs including both pre-ignition and detonation events.
As just one data point, having read some of them, I removed the Champions from my plane (SR22 N/A, Continental 550 engine) and found not a single one of them in spec for resistance. I replaced them with Tempest massives.
More than one data point – here
This subject hit big time on the US sites a year or so ago. I had a 100% or so failure rate of the resistors in Champion plugs.
However, in Champion’s favour (and I think I wrote this in one of the above stuff) they get away with it most of the time because the dodgy resistors still manage to break down (become conducting) before the voltage generated in the magneto breaks down the magneto itself – especially with Bendix mags which take a lot more punishment than Slick ones, apparently. And spark plugs seem to ignite the fuel OK even if the resistor is flashing over completely and is covered in carbon as a result.
I went to Tempest URHM38S finewire plugs which seem perfect, after ~500hrs.