High TIT, CHT, and rough running engine (and changing the magneto type)

Stephan_Schwab wrote:

Having the TAT system means I simply use a certain fuel-flow (16 GAL/hr) and RPM value (2500) and that’s it.

This setting is the same as in my Turbo Skylane with Lycoming IO540, MP 25, RPM 2500, FF 16 G/hr, TIT never exceed 1630 F°.
Full Power is MP 32, RPM 2800, FF 24 G/hr- I need this setting only for two minutes.

And you probably want to check the spark plug on the opposite plug on cylinder 5, as it should have performed like the others if on one mag?

Stephan_Schwab wrote:

I just learned that my right-hand magneto had died. That caused insufficient fuel burn and thus high temperatures

NAILED IT !

What do I win ?

ps: I doubled down if they were Slick pressurized – so are they ?

I just learned that my right-hand magneto had died. That caused insufficient fuel burn and thus high temperatures Good to have two mags

I have had exactly the same 4 weeks ago. I made a replacement for both magnetos. Just to be sure, because both of them had been overhauled just 152 hours ago, and the right one was completely destroyed.

I wonder which shop overhauled them.

What do you mean with “completely destroyed” ? The mechancal side of a mag is no rocket science – and a coil or capacitor cannot be overhauled. That is why I wrote recently coils and capacitors are mortal. A 500 hour inspection does very little for future operation. You can exchange the contact breaker and do a bit of greasing in a few places, the spanner work is trivial. But the lifetime of coils and capacitor are pure luck, no way to do preventive checks on them apart from oven mag spinning test. Even so it is just a momentary check and you can not rely on that for next 500 hours. Obvious reason why there are two mags on an aviation engine – and a lot of rewinders in the motor trade. Now that reminds me of engine specialists – with same problematics . . . . Vic

What do you mean with “completely destroyed” ?

That‘s what I mean.

Now that don´t impress me much about American tech. Looks to me like a broken c.b. blade spring – or was it destroyed by simple complete wear of that plastic “cam follower” plus the first part of the spring blade that carried it , can´t tell from the photo ? There should be an oiled felt somewhere that lubricates the c.b. cam for long operation without friction wear to keep ignition timing. Or is there no such thing on that mag ?? If complete wear due to no lubrication was the cause, then , yes, the maintenance shop has to be blamed for not caring for this . But I guess in this case the spring would have totally earthed the mag in the end, at first the timing would have been all wrong for long time, and you finally had no sparks from it so I guess the spring has broken in flight. Not easy to blame the maintenance company for that, rather the manufacturer for questionable quality. The broken rest of the spring (very short and stiff by design) and plastic follower must have been found in the mag when that was the defect. I only see a lot of dust and debris so seems wear was a big factor. I am not impressed with those exposed plastic gears as well. Just thinking, I have never had a Slick in the hands and do not know details of the contact breaker design . At least the coil should be OK. Vic

This may be why an overhaul is better than an “inspection” because in an OH you change all these parts.