PT20J

Is the B-nut on the end of the hose at the firewall end tight?

I haven’t checked so I’m not saying you’re wrong. But, then why doesn’t my engine sag more or less as the temperature changes? And, wouldn’t the rubber be stiffer when it’s cold making it more likely to pass in the winter?

Bevan is in Wichita. Mid-Continent is a Bendix-King repair partner (fixed my KAP 150) also in Wichita. Autopilots Central is in Tulsa.

There is a spec in the service manual to determine when they need replacement.

Doesn't seem to be much markup. BTW, if you join the Washington State Pilot's Association, Spruce offers a discount. The amount varies depending on the product, but for large purchases it may be worth it. https://www.wpaflys.org/member-discounts

And Cirrus -- I see a lot of younger pilots with money buying Cirrus.

According to GAMA https://gama.aero/wp-content/uploads/GAMA_2019Databook_Final-2020-03-20.pdf, the average pilot age is: private 48.3; commercial 45.9; ATP 50.8. It would seem to be a reasonable assumption that the average age of pilots that own aircraft would be higher than the general pilot population.

That was a while back, but I believe he does have a 3D print file for ETA switches now.

I loosened everything and then tightened the B nuts first while rocking the gascolator forward. Then, I tightened the screws in the cockpit. Now it aligns. What the factory did is sandwich the floor between two large area washers at each screw location which deforms the floor slightly to tilt the gascolator to match the hole in the belly panel.

Did you use a slo blo fuse? Breakers may take longer to trip than a fast blow fuse. A better test The covers snap on and off. I believe @AH-1 Cobra Pilot can sell you replacements and answer installation questions.

It's a Mooney part so it's unlikely to find a new one unless some MSC has new old stock sitting on a shelf somewhere. Probably lots of used ones around removed from airplanes that have been upgraded to engine monitors. Have you tried eBay? However, if I were to buy a used one, I'd send it out to a shop to have it overhauled anyway. It's not that expensive and then I'd know it was accurate.

Maybe the cylinder is just worn out. The piston looks like there has been a lot of blowby. I think the varnish on the skirt is caused by hot combustion gasses getting past the rings and oxidizing the oil. How many hours on it and can you make out any crosshatching or is the cylinder pretty smooth (it's hard to tell in the pictures)?

It's just a bad design. The limits are actually only 11 deg left and 13 deg right -- much less than other airplanes. And, until the later models the only stops were at the rudder. Even the later model stops are not very strong.

Maybe. If you shorted a shunt line to ground that would put 12V across the ammeter which is actually sensitive to millivolts. But, if the meter were dead, it should read zero. Sometimes when you overdrive a meter the needle just sticks so I'd try tapping on it to see if it frees up. Are you sure that all the wiring is correct after you fixed the problem? Skip

Just move your nose wheel from stop to stop and mark the position of the pointer on the turn indicator. The vertical bands go just outside the pointer.

When you do the compression test, remove the dipstick and listen for where the air is escaping. If it is hissing out the dipstick tube, it's getting past the rings. If it is hissing out the tailpipe, it is getting past the valve (rarely it may hiss out the air filter due to a problem with the intake valve). An oily cylinder with bad rings can have good compression because the oil seals the rings. (It was an old diagnostic trick on autos to squirt some oil into a cylinder with low compression and see if it improved to isolate a ring from a valve problem). A lot of times you can fool around rocking the prop back and forth (stand well clear - if you move it too far it will spin on you) and significantly change the compression readings as the rings move back and forth in the grooves. There is actually quite a bit of play there. Skip

Thanks Paul -- that is clearer than the email. But the devil is in the details. Would we be getting some sort of commentary on pictures submitted (sort of like Blackstone does with oil samples) or some blanket statement that the cylinders look about average for your cohort? The problem is that we need to learn something about how to interpret these pictures. I think everyone is pretty clear on exhaust valve heads. But what about deposits on the back side? What's normal? And how do we get good pictures of cylinder walls? I find it difficult because the walls reflect so much light that there is a lot of glare and it screws up the autofocus. How do we know for sure the difference between a scuff and an oil smear? How much scoring is normal? Lycoming piston pin plugs are suppose to rub on the cylinder walls, but how much burnishing is normal? So, for instance, what would you have to say about the OP's pictures? I think most of us that responded admitted that we really don't know a lot about interpreting these things. Skip

What worked for me was taking a pump oil can full of fluid and filling all the lines and master cylinders as much as possible before tightening the connections (messy). Then I opened the bleeders and let it drip until I ran about a quart of fluid through the system. Then we let it sit for a day before bleeding it bottoms up. My IA claims that most of the problems come from rushing it and that letting it drain and sit for a while helps. I don't know if it does or not, but it worked for me. He also told me that Cherokees are the worst (5 master cylinders including parking brake with lines running up and down and all around); it once took him two full days to bleed a Cherokee. So, at least something is worse.

Did you call Vantage? I have found that they sometimes have parts that are not in their online catalog. If you cannot find one, it would be really easy to make one. Just get a piece of 1/16" thick ABS and bend it in a U shape to cover the metal handle, trim it to fit, drill holes in it and paint it. It's a fact that sometimes we have to make parts for these old airplanes. Skip

If I did the ring flush and thought it made a difference, I would then do an extensive run up including some full power runs and then borescope it again to see if there is oil in the cylinder. If not, then I'd fly it a couple of hours orbiting the airport at perhaps 3000' AGL (I did this when I put on the new engine) and land and check oil level and borescope the cylinder again.

We now have so many tools such as engine monitors, oil analysis, borescopes, that we see things in this 80 year-old technology that were probably always there, but we didn't know about before, and so it is difficult to know what is normal. Exhaust valve distress is pretty easy to see, but what does some pitting or cylinder scratches portend? Lycoming told me not to worry about scratches where you can see the cross hatching through them because they are superficial and normal and don't hurt anything. If you can catch a scratch with a sharp pick then it might be a problem. Will a broken ring always scratch a cylinder? I don't know. If you notice an increase in superficial scratches, is that a problem, or will a broken ring always make a deep scratch? A little corrosion probably just increases oil consumption somewhat. But, how much corrosion is too much? I just got an email from Savvy announcing that it is launching a borescope analysis product. Maybe someone will come along and give us a sample of what we might expect. Skip

BTW, if you don't want to bother mixing up Mike's flush brew, my IA says he's had good success freeing up stuck rings with Marvel Mystery Oil. (MMO is mineral oil, Stoddard solvent, a little TCP and some dichlorbenzene (plus red dye and peppermint fragrance ) I'm not a chemist, but according to Wikipedia, dichlorbenzene softens and removes carbon from metal surfaces. Marvel_Mystery_Oil.pdf

I purchased my airplane in 2018. The engine was burning about 2 hrs/qt. Don Maxwell did the pre-purchase inspection, which I personally witnessed. He reported minor pitting and some oil in the cylinders (he used an old style optical borescope that did not have a camera). Compressions were all in the 70's, the oil filter was clean and the last oil analysis done about 20 hours previous showed no unusual wear metals. Except for burning oil, the engine ran fine. About 40 hours later I put it in for annual inspection. Cylinder #4 had a compression of 58/80, there was metal in the filter and a piece of ring in the suction screen. So, engines can degrade slowly, or they can go bad pretty quickly. Skip

The ring flush shouldn’t be controversial and cannot hurt anything. I would give it a try. Maybe the ring is just stuck. I definitely wouldn’t fly it. I had an oil control ring break and it took out a chunk of piston skit, trashed the cylinder and ran metal all through the engine. The good thing about removing a cylinder is that it gives you an opportunity to inspect the cam. Mike Busch is correct that removing a cylinder should be a last resort rather than a first reaction, but I think he’s made pilots overly fearful that it will cause your engine to come apart somewhere down the road. Aircraft engines are designed for cylinder replacement in the field and, done by the book, it is a routine procedure as @N201MKTurbo says. Skip

Easy to swap probes and see if the problem stays with the cylinder or follows the probe.