Buying a M20K

[lawrencedudley]

Hey Guys,

First post on a forum I've already found really useful.

A few friends and I are purchasing a beautiful Mooney M20K. While we have experience with other aircraft, we are not Mooney experts (yet!).

Are there any gotchas with pre-purchase inspection we should be aware of and/or anything notable that we might get tripped up by when flying it?

Apologies if this has already been done to death elsewhere!

Edited September 19, 2016 by lawrencedudley
Wrong type in title

[gsxrpilot]

Done to DEATH!  Hahahah... but seriously... get a pre-buy done by a specialist Mooney A&P or shop. It's a GREAT airplane and one we're all very passionate about on this site. I've had two and can't imagine owning anything else on my budget. But they are unique and require someone who knows what they're doing.

Tell us where you are or where the plane is and we can suggest a good A&P for the pre-buy.

[Mooneymite]

Just now, lawrencedudley said:

Hey Guys,

First post on a forum I've already found really useful.

A few friends and I are purchasing a beautiful Mooney M20J. While we have experience with other aircraft, we are not Mooney experts (yet!).

Are there any gotchas with pre-purchase inspection we should be aware of and/or anything notable that we might get tripped up by when flying it?

Apologies if this has already been done to death elsewhere!

Depending on who is doing the pre-purchase inspection, you may not need any "pointers".  However, if your pre-purchase is being done by a non-Mooney guy, there are definitely some gotchas.

Can you tell us who is doing the PPI?

Edited September 18, 2016 by Mooneymite

[carusoam]

Welcome aboard Lawrence.

I have followed this approach...

1) PPI - Pre-purchase inspection using a qualified mechanic.  Protects your wallet.

2) TT - Transition training using a qualified CFII.  Protects your hide.

3) PA - Purchase Agreement. Write down everything you agree upon.  A few days later some things become challenging to remember.

Each of these is better to have, than to go without.  Spreading the cost between multiple owners makes perfect sense.

Good luck acquiring the new bird.

These are only private pilot level ideas.  I am not a plane salesman.

Speaking of plane sales...

Have you visited All American?

http://allamericanaircraft.com/Default.htm

Best regards,

-a-

 

[rbridges]

Welcome to the forum, Lawrence.  Put your location info in your profile.  It helps others give you advice based on where you live.  

[One Whiskey Hotel]

I would also add, don't be afraid to pass on any airplane if you don't 'feel it,' I waited a long time for mine and am glad I waited.

[N9201A]

Welcome Lawrence! From where do you hail? What's your flying experience? Those facts can help folks tailor responses to be most useful.

[lawrencedudley]

Sorry - I did think it would be a case of this question having been asked a lot.

We're UK-based as is the aircraft. It looks to be in good condition, engine was zero-timed 14 years ago but has only 350 hours on it. One of the cylinders is a little low but this is being resolved prior to purchase.

Anything scary about under-utilised, on-condition engines other than the obvious? It's also the older GB not LB fit. We've flown in it and it sounds great for what it's worth.

Purchase Agreement - this is a very good idea. We're drawing one up with all the little issues in that will be resolved by the seller.

We've had an engineering report from the engineers that currently maintain the aircraft - would you suggest an independent survey as well?

[Hank]

It's often a good idea to have a Pre Purchase Inspection done by someone who has not been maintaining the airplane, but who knows Mooney airplanes and what to look for. The purpose of the inspection is to,protect yourself from hidden problems that the current shop may not have noticed.

I agree, your engine terminology sounds more like a turbocharged engine, not a normally aspirated one.

Happy hunting, we all hope you find a good plane. Maybe Andrew can offer some UK advice.

[lawrencedudley]

Apologies, yes, it's a 231, so the K model. I thought the K/J were the other way around. Doh.

Andrew - if you know anyone you would recommend who is familiar with the type in the UK that would be a massive help!

[gsxrpilot]

The GB engine is the least desirable of all the engines that were ever put in a K. I would make sure my offer reflected that.

[lawrencedudley]

We've reflected that in our offer - the seller (perhaps unsurprisingly) says he's never had an issue with it.

What should we be aware of in terms of the GB from an engine-management point of view? From what I understand it's really, really important to watch the manifold pressure and never over-boost it?

[Zwaustin]

20 hours ago, lawrencedudley said:

We've reflected that in our offer - the seller (perhaps unsurprisingly) says he's never had an issue with it.

What should we be aware of in terms of the GB from an engine-management point of view? From what I understand it's really, really important to watch the manifold pressure and never over-boost it?

Probably going to run hotter in general than a non GB due to different (smaller) throttle body and intake tubing designs than an LB. As far as over boosting or lack there of, my opinion is that once your used to the throttle it isn't hard to manage it, just don't throw it forward because when the turbo spools it is going to jump up. Set it, let it creep up and then fine tune adjust from there. At my airport (550msl) I need far less than 3/4 throttle to make full power and as with any turbo you can easily over boost when down low. When you go to OH it will be updated to an LB and if you want you can spend some money then and add an intercooler and a merlyn upper deck controller. I would most definately question the engine being that it is 14 years old with 350 hrs, that isn't much activity over the years. If there is an issue/ corrosion/ etc, it may take some time to show up thus becoming a costly endeavor. You should look for something that is being flown or has flown recently. Lastly, ask the seller what type of temps he runs it at, if he consistently runs it over 400 on the cylinders I would tread carefully even more so if he tells you that those temps are normal. I like my CHT's under 360 and at 380 I am looking for an immediate way to cool them back down. My 2 cents! 

[LANCECASPER]

If it was overhauled 14 years ago it should have been upgraded to an LB.

[Hank]

11 hours ago, lawrencedudley said:

Apologies, yes, it's a 231, so the K model. I thought the K/J were the other way around. Doh.

Andrew - if you know anyone you would recommend who is familiar with the type in the UK that would be a massive help!

@Hyett6420 Please pick up,the white courtesy phone, you've a fellow Brit on the line!

[lawrencedudley]

@LANCECASPER My reading into OH suggested that it should have been upgraded to the LB as well but weirdly the plate on the engine definitely says GB. Odd. It was overhauled by Norvic - we're still due to check out the log books so will know more then.

@Zwaustin that's really helpful, thank you. We're going to test-fly it again before committing to purchase so will check out the temperatures in detail then.

In summary, is the consensus that an aircraft that's been flown so little, with a GB engine, a bad idea?

[Hank]

The concern is that any aircraft engine is flown so little. It invites the camshaft to corrode, then more operation will result in spalling, ruined (worn away) lifters, power loss and an expensive overhaul.

[DonMuncy]

I have heard that the Continental engines, due to the camshaft being mounted lower in the engine, are less prone to rusting and spalling. Has anyone here had a camshaft spalling failure in a Continental?

[Guest]

47 minutes ago, DonMuncy said:

I have heard that the Continental engines, due to the camshaft being mounted lower in the engine, are less prone to rusting and spalling. Has anyone here had a camshaft spalling failure in a Continental?

In my experience Continentals are just as prone to cam lifter issues as are Lycoming engines.  Continental even has an SB describing allowable conditions.  The only saving grace is that you can pull/examine the lifters without engine removal.  

Here is the SID, http://www.tcmlink.com/pdf2/SID05-1B.pdf

Clarence

[Mcstealth]

9 hours ago, lawrencedudley said:

What should we be aware of in terms of the GB from an engine-management point of view? From what I understand it's really, really important to watch the manifold pressure and never over-boost it?

Good luck and welcome to the site.,

At this point, the engine is a roll of the dice. Some on this site have had minimal issues with this exact scenario, others have been less than lucky. If you get 100 or more hours, hurray. 500? Dance a jig. 

If you have already addressed this issue in price with the seller, then so-be-it. That decision is/has already been made and you move on to other decisions. Any in your group an A/P? That sure would help

good luck.

David

 

[N231BN]

14 hours ago, lawrencedudley said:

@LANCECASPER My reading into OH suggested that it should have been upgraded to the LB as well but weirdly the plate on the engine definitely says GB. Odd. It was overhauled by Norvic - we're still due to check out the log books so will know more then.

@Zwaustin that's really helpful, thank you. We're going to test-fly it again before committing to purchase so will check out the temperatures in detail then.

In summary, is the consensus that an aircraft that's been flown so little, with a GB engine, a bad idea?

There is no requirement to "upgrade" to a -LB at overhaul and continental doesn't recommend converting models. It isn't always done on -GB's because the cost/benefit ratio isn't there. A -GB with GAMI's is better than a -LB without. The money is better spent on an intercooler. Sorry to be so blunt but there is no hard data to suggest otherwise.

As to your last question, it is definitely a concern having sat this long but it really depends on the atmosphere where it sat. My 231 sat 11 years with 1300 SMOH and I have over (fingers crossed) 150 trouble-free hours since bringing it back to life.

 

FWIW the main difference in GB vs LB is the throttle body and the first half of the curved intake tubes. There are minor differences in the injection system, it runs at a lower pressure.

[aviatoreb]

8 hours ago, Hyett6420 said:

Apologies i have been travelling (in a mooney of course). 

I dont know the 231 however i used Riad in London Elstree Aviation for my pre purchase of my 201.   He is analy retentive about things and not that expensive either.  Failing him Willem in Aeroskill Mastenbroch, Seppe Holland is my "local" MSC and also comes highly recomended.  

First thing to note is to get the Annual done if not already, either by LEA, Elstree or Seppe.  This will give you a pretty good "pre-buy", (obviously the current owner pays for this).  Then while the annual is being done have the prebuy inspection done at the same time.  

DM me if you need any more details and ill give you my mobile and we can have a chat.  @lawrencedudley. 

Andrew

Off topic - maybe better by PM - but hi Andrew - I'm on London on business right now!  Take a look at your PM.