TheAv8r

Keep flying it. 1qt/6hrs is normal, if it's not making metal, you have no indications of a problem.

There was a lot of work done at the same time, so it was down for 3.5 months all-in-all. The one piece panel all-in for parts and labor was $3600. I was going to have to have new panels done regardless, to cut new panels, powdercoat and install it was $2200, so $1400 delta to greatly improve the look and flow.

I have a 65E and redid my panel to a flush, 1-piece panel which I highly recommend, it really cleans things up and modernizes the panel. I have dual G5s, but there were no issues with the instruments changing to not have the left side jutting out.

It's also part of the 100hr AD, AD 73-21-01 which requires lubrication of the flight controls and checking the over center torque of the gear. +1 to cliffy, it's not hard. Jack the plane up, use the proper tool fitted correctly on to the joint (maintenance manual even has pictures for this) and a torque wrench to check it.

Do you have an EGT sensor? If the EGTs aren't fluctuating much, a 1gph oscillation would cause them to fluctuate, therefore, it's the sensor.

FWIW, there are multiple Mooneys at my home field that have had similar experiences with Maxwell that I have seen first hand. From mistimed mags to improperly installed avionics to messed up paint, etc. I believe they are extremely good for very Mooney-specific problems, but you should use caution when it comes to typical maintenance, likely related to what Rich said above.

GMax Aircraft: https://www.gmaxamericanaircraft.com/

I think this is the plane you're looking at: https://www.trade-a-plane.com/search?category_level1=Single+Engine+Piston&make=MOONEY&model=M20E+SUPER+21&listing_id=2437216&s-type=aircraft Several things to dive into deeper with the seller: "Recent top overhaul in September of 2024, Crankshaft replaced during top overhaul." You cannot replace the crankshaft simply by taking the cylinders off the plane. The case has to be split. So they split the case, replaced the crankshaft, but didn't touch the camshaft or tappets, and put new cylinders on it. This is some kind of bastardized half-overhaul, the camshaft on Lycomings is also infamous for spalling and corroding early so since that wasn't replaced and this engine wasn't flying, it could be next. OH in 2005 with 600hrs on it = 30hrs/yr flown on average, which isn't great too, maybe related to why they replaced the cylinders. Need to better understand the story of why they did this and why the split the case but didn't do an actual overhaul. Major patchwork on engines without actually doing a major tells me they're cutting corners to save costs, and since the aircraft sales broker did it, they probably are trying to do the minimum to get the plane in a sellable condition. "Gear up landing 1965, off airport landing 1981, minor airframe repairs 1989 and 1991" All of these are old, so probably not a problem, but that's a fair bit of repairs, worth digging into the logs to see why the repairs were done, how extensive they were, and that they were done correctly. "New fuel tanks 1996" No other mention of a reseal is made, and they don't specify if these are bladders, if they are not, I could almost guarantee you're in for a reseal soon.

I would definitely encourage you to do it! I would also encourage you to get some Mooney-centric training from someone who really knows the airplanes. You're going from flying very simple, fixed-gear, slow airplanes to flying a rocket ship that requires a lot more finesse to fly and that comes with a learning curve that may be harder for someone your age, or might not be, totally depends on how you learn . In addition to the gear system, your planning around airspeeds, slowing the plane down, it's also just the speed you have to think to stay ahead of the airplane is going to be drastically different than your C150 or Cherokee. Having a good 10-15 hours with a Mooney CFI will help you a lot as you transition over. You might want to get a few hours in a Mooney before pulling the trigger on buying one to see how it feels. I have a '65 E - they're awesome airplanes. My favourites of the Mooneys, still nimble and crisp to fly as a short-body but they climb like a rocket ship and are fast and economical. At 65% power, 20 degrees LOP, mine does 142-145kts TAS depending on altitude at 7.7gph. That's my favourite place to run it for XCs. Speeding it up to 75% power at 150deg ROP I see 155kts TAS. As far as what to look for, sounds like you already know the basics when looking at planes so will focus on the Mooney things: When were the gear pucks last replaced? Those are age limited and semi-expensive to replace Fuel tanks - are they bladders or still a wet wing? If a wet wing, when was it last resealed? If > 8yrs, you might have a reseal in your near future ($5k or so) Does the prop hub have the 100hr AD? It's an annoying AD if you fly a lot, the -B hub is well worth it. Corrosion - particularly looking at the spar caps, and under the rear seats with the interior out, and the tubular steel cage, those are the most prone areas to getting it. Inspect the induction boot - this is a mostly unobtanium part right now if it tears, so you'll want to ensure it's in good condition

This one checks all of your boxes, the asking is $105k, but that doesn't mean you won't be able to snag it for $100k. The only thing not mentioned is how frequently it is flying. https://www.trade-a-plane.com/search?category_level1=Single+Engine+Piston&make=MOONEY&model=M20E+CHAPARRAL&listing_id=2439515&s-type=aircraft

I have a JPI 930 installed on my M20E, probably 250 hours on it, 0 issues.

Also strongly advocate for CIES senders properly calibrated. My CIES senders are incredibly accurate, to 1/10th of a gallon, so at all times I know exactly how much fuel is in my airplane. I never fly with less than an hour reserve, but it has brought so much peace of mind when trying to make decisions on fuel planning.

Yeah, I've interpreted it the same way, there's 52gal of usable total fuel, and then an additional 0.5-ish gal of unusable (I have a '65 E with bladders).

FWIW consider all of the accessories too. I OHed the prop, put in a new prop governor, all new oil and fuel hoses (required per Lycoming's SB FYI), new baffling, new hardware, OH the engine mount, etc. Add in labor and by the time it's all said and done, it's $60-70k.

I overhauled my IO-360-A1A engine in November of last year with the engine being delivered to me finished in June. At that time, you could not get new A1A cylinders (2yr lead-time) so mine were OH. The base OH charge was $28k, I added in some things that brought the final up to around $33k. This was from a well-known reputable overhaul shop.