pilot_jb

Bumping this up for added photos. Still looking...

It's definitely closed now. All you get is a, "Sorry we're closed" sign that fills the screen. It's a real bummer. I've order a fair amount from them in the past.

I don't know your mechanic, but if he saw this and didn't realize what was going on then there is a major issue with his skill level...and there's no way he didn't see it. This sort of failure will usually also show up in the exhaust pipe and on the belly, as well as the plugs...even before a possible low compression reading. Borescope inspections are also your friend and should be conducted regularly. I look in my cylinders during each spark plug service, and at the back of the exhaust valves (more relevant here) while the exhaust is removed at annual.

Did no one else here notice that RTV was previously used when the sump gasket was installed? Probably doesn't matter at this point, but did you check the sump bolts for proper torque? With RTV under there, which it shouldn't be, the torque would have never been "correct" and will change over time.

As stated, it’s the inboard and forward mist inspection plate. Under the wing behind the leading edge but in front of the tank. There’s two on the plane like this; one on each side. These two are two-piece construction and are the only inspection plates made this way. Someone way before my time fabricated one from a flat piece of aluminum and I want to make it right.

SUCCESS! 1967 M20F. This is the inboard and forward most oval inspection cover that is two piece construction with seven (7) screws. Must have the nut plates attached. Thanks!

45G is my home airport. We have at least three Mooneys on the field. Basically, we have a grass runway with a paved centerline.

Simply this to tie the yokes together. Simple, cheap, and very effective. https://www.amazon.com/gp/product/B07GN9MJRR/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

We end up pulling the mags. The points and the rotor were shot. Fixed it right up.

A ground mag check produces a 200-300 RPM drop with what I consider to be a rough running engine. Plug timing was set approximately 20 tech hours ago.

Not a formal engine monitor, but a Mixture Mizer. This is an instrument that shows peak EGT for one cylinder at a time, but not actual EGT. It will display actual CGT. Also, it does not record data. Finally, I do have an EI EP-5L fuel computer, but, again, all of my readings and data recording are manual.

About to start really digging in... Went through a period of time when I would Intermittently fail a left mag check. The issue started happening progressively more often, so as the first step in diagnosing the problem, we swapped plugs from the right to the left. The expected result was for the problem to move to the right if it was the plugs, and to stay on the left if it was the wires or magneto. Oddly enough, the issue corrected itself. Temporarily, and always on the ground, both mags passed with flying colors under warm and hot scenarios. I let the plane cool and then the problem returned. We then found the timing to be, at most, a couple degrees off. After this was corrected, I once again could not get it to fail a check on either side. I let the plane sit for a couple days, and now the issue is as bad as it's been...can't get it to pass on the left. We also rebuilt the P-leads, because we found the left side wiring to be old, brittle, and only connected by a few strands of wire. Both mags have 512 hours. IO360-A1A Bendix S4LN-200 shower of sparks Left dropping between 200-250 RPM with the last round of runup's showing a 300 RPM drop once. Bottom number 4 plug is slightly wet with oil, but is not totally uncommon and should not be enough to cause the drop My planned next step is to pull the mags, which is going to be a total PitA. Is there anything else I/we should look at prior to pulling them? If pulling them is the only option, who is the recommended mag shop for Bendix? Thanks!

I don't have access to the map, but am wondering if I'm listed. If not, I would like to be. Thanks!

Gentlemen, For reasons we won't discuss, it's come time for me to negotiate the value of my M20F (No...I'm not selling her). I need a recommendation for a fair, trustworthy, appraisal in the southeast Michigan area. Thanks!

My sincere apologies that this took so long. My Mooney and I have been racking up CC time.