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Thoughts on revitalizing an under-utilized M20J?


ThorFlight

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Greetings everyone!

I’ve been lurking here for awhile now have been grateful for this excellent source of information about my favorite make of aircraft.

Now I’m ready to make an offer on a ’89 M20J, but would appreciate your advice before I do.

The aircraft in question lives in the midwest, stored in a heated hangar and had regular annuals, with the most recent this past June. It appears to be in above-average shape, with one important exception: it has only flown about 70 hours over the past 8 years.

It has a reman with ~200hrs on the tach, separate mags and roller-cam lifters. From my research, there doesn’t appear to be enough information to conclude whether that will definitely help avoid a spalled cam and early retirement of the engine. That said, from a review of the logs there doesn’t appear to be any red-flags beyond the disuse.

Other than engine corrosion, I’m concerned about firewall-forward items such as prop-seals, hoses and then pucks and tank seals if it wasn’t stored with full fuel; any of which may need attention in the not to distant future. Some of them can be easily spotted in a pre-buy, but I’m particularly concerned with those that are not readily apparent and would show up later.

Given this, I’m curious if anyone here has any experience with bringing an under-utilized aircraft back to regular operating status, and the types of issues that were encountered and any recommendations for someone considering this path. Would you do it again, or find an aircraft that's been in regular use?

Looking forward to getting to know you all.

Thanks.

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My C lived in a hangar on the WV/OH border that was sometimes heated in winter, and flew 9 hours the two years and a bit before I bought it. The tanks both had small leaks, and this was factored into the price; I did a full strip and reseal three years later. No other problems have surfaced related to it's idle time. Tires, vacuum pump, new pucks, etc., sure, those happen. 

But you're looking at triple the sitting time. Check the logs and see how the 80 hours are distributed between annuals. It could be 10 hours a year, it might be 50 hours in one year, then none for a couple more. It could make a difference.

Good luck in your search!

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Not being a nit-picker or a smart-ass, but would you prefer getting a plane that sat idle for 5 years, then flew 25 hours a year for the last three;  or one that flew 10 hours a year for the last 8 years.

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Not being a nit-picker or a smart-ass, but would you prefer getting a plane that sat idle for 5 years, then flew 25 hours a year for the last three;  or one that flew 10 hours a year for the last 8 years.

The time appears to be evenly split over the 8 years at about 10h/yr - give or take.

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2 minutes ago, ThorFlight said: Good idea. I was also thinking of asking the seller to agree to put some of the purchase price in escrow until the engine proves it's status. Anyone here ever done that?

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I would personally be offended by that request and not want to do business with you.  There are no warranties on quarter century old machines. I guess you could try it, though. Perhaps your seller will feel differently.

Jim

Fair point. I would prefer to price the risk into the offer, but the seller is confident in the low-time and roller-cam. If we can't meet at a mutually agreeable price, the escrow might bridge the gap.

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38 minutes ago, ThorFlight said:

I’m curious if anyone here has any experience with bringing an under-utilized aircraft back to regular operating status, and the types of issues that were encountered and any recommendations for someone considering this path. Would you do it again, or find an aircraft that's been in regular use?

I've done that with three different airplanes. Each had flown very little in the previous few years and I negotiated the sales price with the expectation of having to replace all the "rubber goods" minimally and potentially some other stuff. For the 1958 Cessna 182A, I put zero dollars into maintenance beyond normal oil changes, etc. For the Twin Comanche, I replaced all of the engine baffles, although to be fair that was not an airplane dis-use maintenance related expense. For the P337, upon landing when getting the airplane home, it had no right brake. My IA refilled the 5606 and cleaned up around a seal and it was fine.

Definitely negotiate price based on anticipation of significant maintenance, but I doubt you'll actually have to spend the money.

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1 minute ago, ThorFlight said:

Fair point. I would prefer to price the risk into the offer, but the seller is confident in the low-time and roller-cam. If we can't meet at a mutually agreeable price, the escrow might bridge the gap.

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If I were the seller and the buyer wanted funds in escrow for the engine, my concern would be the buyers experience in flying with an engine that requires some knowledge to operate properly. In my opinion, you're asking him to become a silent partner, albeit for a specified period of time. 

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1 hour ago, ThorFlight said:

Engine installed in Nov. 2007.

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So from a TBO standpoint it has 8% remaining.  Not that I would pull it off and overhaul it, but there is significant risk of an early demise. 

We rolled the dice on a 1300 hour 12 year old flat tappet engine that was flown regularly up until 2 years before we bought it.  After a year and 250 hours the cam spalled, we ate the entire 35k cost of an overhaul. It sucks. 

Edited by jetdriven
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You are kind of looking it wrong.  The damage if any was done each time it was started after sitting.  So it's not like you have a chance to do something to bring it back.  Roller cam is better than flat. Have an extra $10K to bring it back to airworthy.  Hoses and pucks and tires oh my.  Do a cold compression test and and then a hot one.

 

 

Edited by Yetti
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I'd present a different thought, with the sellers agreement pull two cylinders either left bank or right bank.  Examine the cam and lifters.  If everything is good move forward, if it not good the seller pays to repair.  No one waits for money and the risks are reduced.

Clarence

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I'd examine the cylinders as well. I'd bet at least a couple have heavy rust pitting as well. The cam may be rusted in places but you'll have to see it to determine that. 

How to value it? Take 1989 m20J market value.  Then deduct for risk of future repairs. Tank seal is 10k. Biscuits 2k laid in. Gyros, 500-700$ each unless it's king stuff then much more.  Prop corrosion or reseal needed. Engine.   This board is full of people who said I bought a Mooney got a great deal, then they  dump 40K into it. One guy ended up 40K into a rebuilt flat tappet motor alone. Another has rear spar corrosion and totaled it. Needing a full Tank reseal is another common topic here.  So you have to accurately forecast risk and cost and apply that to market value. 

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I was planning to have the engine bore-scoped as part of the pre-buy. If there was evidence of corrosion there, I would assume that the cam is compromised too.

Even if the seller is willing, I have concerns about pulling multiple jugs as that is pretty invasive, is it not? Should I not be concerned about that?

However, the definitive information coming from that procedure would be beneficial to all parties regardless.

All great info here, guys!! Thank you.

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It is possible to have cylinder wall corrosion and still have a clean cam.  The only way to know is remove cylinders, which is not a big deal for someone who knows what they're doing.

Clarence

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Our airplane sat untouched for 10 years in a hangar in northern CA.  They had LASAR make it airworthy before LASAR sold it to us.  LASAR did over $30,000 worth of work on it including replacing all the hoses, repaired the autopilot, every piece of electronics, prop, magneto, tires, brakes, etc.

As for the engine, they did nothing internally.  After we bought it, it developed morning sickness, probably from too many years of running ROP.  Since we got that fixed and started running LOP, we have had no more problems.  The first oil analysis had almost every metal in the red.  We then changed the oil, flew it for 25 hours and did another analysis.  Everything was in the green and has remained so for the past 3 years.  We assumed the first analysis was seeing all the surface corrosion being scraped off.  Once that was gone, there did not appear to be any continued excessive wear.

I liked the idea above of pulling cylinders and looking inside.

I also would consider asking the owner to fly the plane maybe 2 - 5 hours, then do an oil analysis and check the filter for metal.  Change the oil and fly it for 10 more hours, then do another analysis.  If the second one comes back clean that would be a good sign.  It would also give you a chance to see what type of oil consumption it has.  Ours has consistently gone through a quart about every 5 hours +/- since we got it.  He might be more willing to do the flying with you if you agree to buy the gas.  If you fly with him, it would also give you a chance to become familiar with the plane.  Put an instructor in there with you for part of the time and you could even meet any dual time requirements the insurance company might have.

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Escrow thing seems like a bad idea.  Clarence has a good idea. 

Given probably since not so many hours since OH but some calendar time, you would likely benefit from an IRAN rather than a full OH.   Case and crank are most likely not an issue.  Cyls could be fine +-.   Cam is to be worried about but that's still a replaceable item even if the case needs to be split.  IF the case needs to be split for the cam would be worth considering a full top unless given the propensity for valve train issues. 

Shadrach has experience with IRAN instead of overhaul costing significantly less and getting excellent results for a cracked case - but he's handy and did R&R with his IA.  JClemens recently told a great pictorial story about cam spalling that is worth looking up.  

No a's or p's just the PPL who worries about his cam.  

-Brad

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4 hours ago, jetdriven said:

So from a TBO standpoint it has 8% remaining.  Not that I would pull it off and overhaul it, but there is significant risk of an early demise. 

We rolled the dice on a 1300 hour 12 year old flat tappet engine that was flown regularly up until 2 years before we bought it.  After a year and 250 hours the cam spalled, we ate the entire 35k cost of an overhaul. It sucks. 

Almost the exact same thing happened to me with my J.  And there are others here on this forum that have had similar experiences.... Sadly.

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I bought a 77 J that had been sitting for 7 years.  Just went ahead and overhauled the engine even though it had like 800 hours.

I would beware of little things like the wires, fuel tanks and such.  We had a bunch of little stuff like that.  It all worked out and I'm very happy but it does chew through cash initially.

 

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Pulling a couple jugs to inspect the cam/lifters is a great idea, but don't expect the seller to agree to it. I tried negotiating that when I purchased my J and the owner would not consider it. Mike Busch suggested an escrow account for a specified time to address possible cam/lifter issues but the seller wouldn't go for that either.

I ended up making an offer (below asking price by a fair amount) and following a typical pre-buy we completed the deal. I've got 400 hours (post purchase) on it now with excellent oil-analysis results but of course that could all go to hell tomorrow. I sure hope not.

Good luck!

P.S. When did Lycoming start selling roller-tappet IO360s?

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As a guy who's represented parties on both sides of similar transactions, escrow is usually a good idea. Where you can't agree on it, there's a reason. Never had someone tell me "wish I had skipped escrow." But I've lost count of people who were sorry they didn't do it. I believe AOPA even has a service for members. Easily done.

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