AndreiC

Unless you have a wet vacuum pump (unlikely, from what I know), the dry pumps either work or they don’t. When they fail they fail catastrophically. So if it still shows 4.2” it means the pump is probably still good.

If it was tumbling and spinning like crazy I think it may be more likely the vacuum pump. The AI does not need to go crazy. Easiest to check would be to turn the engine back on, revv it up to 1500-1800 rpm, and look at your vacuum gauge. If it is not showing 5” your pump is toast. I was in your situation not long ago, and chose to replace my DG with a good used one. (In my case it was the DG that was bad, but only in the sense that it had a lot of precession). I paid about $400 for a used one, and compared to the cost to install a G5, especially as a DG to interface with the autopilot, I felt it was a steal. But I am happy to stay with steam gauges for a while, people have been flying with them for decades and planes were not falling put of the sky because of this.

Does this also include 1-800-WX-BRIEF that they plan to decommission? I use that service pretty regularly. It is useful to me when I am in doubt for a go/no-go decision, it is more helpful to have someone else tell you basically "don't go".

Poplar Grove, IL is a well known shop. They do many engines. I have not had engine work done by them, but I've known of themfor over 25 years. They seem to be solid, and their work balancing my prop was very good.

Somewhat unrelated question: I have in my panel the original (1970) 8 day clock that came with the plane. Not sure if it is a Waltham or some other manufacturer (pic attached). It works well, but over 3-4 days it loses about 15-20 minutes, which is a lot. Do you guys know if this can be adjusted relatively easily in the field, or does it need to be taken to a watchmaker?

Hot starts in my IO360 work pretty well with the procedure of leaving the throttle at 1000 rpm and cranking with mixture at ICO. (This is, say, 15 minutes after shutting down on a hot day.) But what I don't understand is why, after the engine starts, it will stumble continuously at low power settings (say, under 1400 rpm). Moreover, if I keep trying to run it at 1000 rpm while it does this, I will almost certainly hear backfires from the muffler, which can't be good. My current procedure is to run it at a high idle (1500 rpm) for a few minutes, while also running the boost pump. That seems to work, but I don't know why it does that. My guess is that there is vapor lock in some of the injector lines, and somehow fuel gets in the cylinders that does not burn and explodes in the muffler. Why? I don't know.

Speed difference is probably not more than 5-10 kts, if even that. E and J are both fuel injected. The big difference for me would be the extra cabin space (maybe important? maybe not? I rarely fly with 3 people, most of the time it's me alone or me + 1). and perhaps the visibility from the bigger windshield of the J.

If all other things were equal (avionics, paint, tank condition, engine SMOH and quality of shop, etc.), how much more should a J be worth versus an E? (Ballpark figures, of course.) Is it 30% over the value of an E? 50%?

Are you looking for the original, factory dimmer electrical diagrams for a 1970 Mooney? I have them (there are two versions) somewhere, I can look them up.

Yes, thanks for asking. The flight in was fine. Lots of turbulence on the way down, but smooth air above 4000’. Very strong headwinds, 45-55 kts — at some point I joked with a controller telling them that I lied I was a Mooney, I was in fact a C150. The storms passed close to the airport, and made me nervous as we were sheltering in place in a gas station, but nothing on the field was affected. I went the next day to check, all was fine, except that the whole plane is now coated in some fine reddish dust, just like our car is. I guess the storm brought in a lot of dirt. I’ll have to wash the plane once I get home…

Do you think Friday morning around 11am will be crowded? I don't like to mess with "good old boys", but then on the other hand 1H0 is the most conveniently located place for where I'll go to...

Any experience with Creve Coeur (1H0)? It is closer to where I need to go.

I need to fly into the St Louis area and stay two nights in the near future. Unfortunately it seems that at KSTL the only FBO is Signature, and they want to charge me $92/night for a tie-down, which I find a bit obscene. Is there some other preferred airport to go to? Lambert has the advantage that where I need to go is quite close to it, so I may end up biting the bullet and paying the fee, but I want to explore other options if there are.

In a previous life I owned a Cherokee which I kept tied down outside. After a period of heavy rains I found quite a bit of water in the fuel, and discovered that the filler neck on one side was pitted. Immediately replaced the gaskets, and my mechanic did two things: 1) Sanded down the pitting till it was more or less smooth, but while being very careful to not get dust into the tank (I don't recall how he did that part). 2) Put some Dow Corning #??? on the lips of the filler necks and on the gaskets of the caps. (I don't know the exact DC number, maybe someone else here knows; it was a clear greasy substance.) This DC grease was reapplied at every annual, and every time I stopped by for other maintenance issues. After this I no longer had any problems with water in the fuel, even though I still kept that plane outside for a few more years. May be worth doing as a temporary measure, since it was a small ticket item. Could prevent bigger issues like what @cliffy said.

The Lycoming guide refers to counting pieces only when they are big enough. Yours is more like dust. For those you use the total quantity (like fractions of a teaspoonful, as mentioned above).

This is not something that worries me too much. My bigger issue is if a KX155 will last another 5-10 years after fixing the display issue, or if this is just throwing good money after bad. And if people are of the opinion that fixing it is the way to go (which I also lean towards), has anyone tried a KX155 with the updated LED displays?

The problem is that it seems new gas plasma displays (or whatever was original in there) have not been available for about 5-10 years at least. So it is just not possible to replace the display with an original one. I was hoping to get some feedback from the list on how good the LED displays are, that are advertised to be good forever. (I am aware that some KX155 units had bad capacitors, which leaked and ruined the PCBs. The two radios I have in hand now, my old one and the one I got from ebay, both look very clean, so this should not be a problem.)

The avionics package in my 1970 M20E consists mainly of a GNS430W and a KX155 (no glideslope), connected to an ancient audio panel (KA134) and a Telex intercom. The radios also drive an STEC/30, either through GPSS or via the VOR receivers. It all works quite well, and as a CB I am happy to not have the latest and greatest if I don't have to pay for it. Lately, however, I have noticed that my KX155 display becomes unreadable in dim light. From talking to a local, highly respected avionics shop (SkyCom in Waukesha) I understand that most likely the display in it is getting old, and it is will probably die slowly in the next year or so, to the point that it won't work even in daylight. Moreover, my KX155 has some other problems as well, like the frequency knob would not always change the frequency correctly (it would jump around a lot). Thinking I was smart, I bought from eBay for around $1000 a replacement KX155 that was advertised as being in good working order. This new one, however, came with its own host of problems. The squelch button did not work (turns out it is a relatively easy fix), but what was even worse is that in dim light this one, too, is unreadable. It is a bit better than my old radio, but I fear it may also be on its way out. From my research, there are a few options: 1) Bite a relatively big bullet, and send my old radio to the guy at KX-155.com. He said that for $2500 he would go through the whole radio, and replace the display unit with an LED one that should last another 25 years. 2) Bite an even bigger bullet, and replace my audio panel with something like the PAR200B ($3250, plus install cost of around $4500), and get rid of the troublesome KX155 altogether. But I would lose my second VOR receiver (maybe not such a big loss), and I would end up with a lower (6 watt versus 10 watt) transmit power. According to the guy at KX-155.com, the KX155 was the best radio ever built (??) and I would not get anything like that communications quality in another radio. 3) Or be cheap, and buy for $720 from ebay a self-install LED solution for the KX155. I have not seen any reports on how well this system works. In any case I would probably either sell my old radio (hoping to get $500-600 for it), or ask the guy who sold me the radio on ebay to take his back: he was offering a 30 day money back guarantee if one did not break the sealing stickers he had put on. However, my avionics shop had to open it up to see what was wrong with the squelch button. What are your guys's opinions on what I should do? Sometime in the future I definitely intend to upgrade to a modern audio panel (I was thinking the PMA450C), but I was hoping to push that decision back by a year or two, given its high cost.

I had an engine fire happen in the first Cherokee I owned (a 140, carbureted O-320). (To be perfectly correct, the fire happened before I owned it ; but only by a few hours). This plane had been sitting for a while when I bought it, it had been inspected by a mechanic and had an annual inspection, but presumably did not get started at any point in the recent months before I went to buy it. I wanted to get checked out in it with a local instructor (I only had minimal time in Cherokees, mostly had trained in a 152), and when he and I tried to get it started it wouldn't start. We kept priming it, until we somehow managed to flood it; fuel coming out of the intakes (or carb, not sure) caught fire. We managed to start the engine and suck the fire in just as local people were running out with a fire extinguisher. The cowling was all metal; we took it out, looked at the engine inside, the local mechanic deemed it fine, and I flew it home after a couple of trips around the patch with the instructor. (The guy was an old timer, and he alleviated my concerns by telling me that these "modern" engines are bullet proof, he never saw one fail, unlike the ones in the Piper Cubs he used to fly, which every once in a while required him to dead stick in a field to clean up the jets or something like that...) Seems like no damage was done in that fire, not even paint peeling on the cowling or anything. I flew that plane happily for a few hundred more hours with no incident. As an aside, I looked up the fate of that plane (N6085W) recently and it was very sad. Some years later the 70+ year old owner ran out of gas in it and crashed it, killing himself and his son who was in the right front seat. The rear seat passenger, the grandkid, survived with some injuries. Damn fuel exhaustion...

Interesting. What I take from this is that my MP gauge may be mis-calibrated, despite having been to the shop not so long ago. Is there a way to check it out somehow? It is the classical steam gauge with fuel pressure on one half and MP on the other. My CHTs were not a problem at all at the power setting I was at. It's true here in WI temps are much lower than in FL, but I was below 300 dF CHT on all cylinders, I could barely keep them in the green. But my impression from reading the Mike Busch articles (and others), when it is cold outside low CHTs are not the whole story -- you want to control internal cylinder pressures, and when it is very cold outside CHT does not measure this accurately.

It is interesting to compare these numbers for your 1966 E-model with my 1970 (also E). Quite a difference! For example, at 2500 feet, all out, 2200 lbs, my POH lists the top speed of the plane as 186 mph, while yours is 197. Moreover, it seems like in 1966 they would still allow best power mixture at 97% BHP (13.8 gph), while in my plane they want full rich anytime you are over 75% power (18.2 gph in this setting). I wonder which of the two speed numbers are closer to reality. I have heard many say that the numbers were inflated by the marketing departments. Presumably more so in 1966 than in 1970, but it is still not clear to me how realistic the 1970 numbers are still.

How do you guys use the performance tables when the OAT is not standard? My temp gauge is unreliable, but the ground temp (1000 ft) was close to freezing, so I think at 6500 it was probably around -10 C. DA is then 5000ft. Should I use the performance tables for 5000 feet, even though these are calibrated for standard ISA?

Certainly more than 5kts. Closer to 9kts. (152 kts -> 143 kts, calculated by the GPS 3 cardinal points method).

Fair enough. I am a bit more concerned about something else now. According to what I looked up, 25 squared at that altitude is closer to 85% power. So I assume running at 50 rop is not at all a great idea, as I think this is pretty well inside the “red box”. I wonder though how accurate these numbers are. My MP gauge was calibrated about a year ago, so I believe it should be showing correctly. But how can you get 25” MP at 6500 feet? Even without induction losses, you would expect at best 29.92-6.5 = 23.42” best MP. Could I be having a leak in my MP tubing? Or is there something else going on?

Sorry, maybe I was not clear about what I was asking about. To me 11.7 gph to get only 50 ROP seems very high fuel consumption. I was expecting more like 10.5-10.8. But no one seems to be fazed out by this number, so it’s probably ok I guess.