Considering an offer...too low?

Well, in my uncertificated, and uninformed opinion, the lower right area of pic 38 would be repair required at next annual. Looks like it could quite easily need a new rib. Add that to the rest of the issues I'm seeing on the airframe, and the long time since major, and my feet are turning toward the door, getting ready to walk.

What started out as a bargain is turning into shiny paint, and a few blinking lights on a 430. The sum of the aircraft is having trouble measuring up at this point.

<edited to correct pic location>
 
Primary concern is airframe corrosion. It is the most difficult to measure, catch and fix. Especially cabin areas that only see the light of day when the interior is removed. Even treatments don't get into these areas as no one wants to stain upholstery while applying the corrosion inhibitors.

http://www.airmod.com/articles/PDF/cpajan07.pdf


Is the engine good? Even if complete trash it is typically easier to remedy than airframe corrosion, with a catch, any unavailable parts that can mess up engine overhaul/repair? (no longer supported crankshafts).
 
docmirror said:
Well, in my uncertificated, and uninformed opinion, the lower right area of pic 38 would be repair required at next annual. Looks like it could quite easily need a new rib. Add that to the rest of the issues I'm seeing on the airframe, and the long time since major, and my feet are turning toward the door, getting ready to walk.

What started out as a bargain is turning into shiny paint, and a few blinking lights on a 430. The sum of the aircraft is having trouble measuring up at this point.

<edited to correct pic location>
Click to expand...
I'm not seeing numbers on the pics to follow along.
 
Specific to the internal part of the engine I talked to the gentleman doing the pre-buy for me and another A&P. Generally they both echoed the same thing.

The bulk of the time since major overhaul is in the last few years, there are regular oil changes and the compression is good still. That generally tells you that the engine is in decent shape, but if there were a problem due to age, it would most likely be evident with a bore scope of all six cylinders.

The mechanic doing the pre-buy is going to bore scope it tonight or tomorrow and record the scoping (from the camera) for review. He said that will cover most except the most extreme cases.

EDIT to add the summary: Generally his message was that if you have a good borescope of all cylinders, good compression, and several hundred hours of flight in the last 5 or so years, as well as regular inspection and maintenance, you have a good indication the engine is decent shape.
 
Last edited:
I just got off the phone with the mechanic that did the last three annuals. I feel a bit more confident now. He definitely recommended the scope of the cylinders and encouraged me to look deeper if I wanted but said the first annual he did was very in-depth, removed the crank. Fixed one seals and said he'd focus more on getting a push button starter installed and a corrosion treatment than anything.

I felt pretty confident after talking for about an hour about the various work he's done.

He said this engine is the "b" model with no shortage of parts
 
So, the more articles I read, the more mechanics I talk to with experience with the O-300 continental, the more I hear the same themes:

The bottom of the engine is rock solid. Shouldnt/wouldnt/dont worry about that.

That particular engine sitting will very likely be fine but not make the standard TBO time, will likely need a top overhaul a few hundred hours earlier

The more you fly these engines the longer they last

Borescope the cylinders and check for cracks in the exhaust valves and call it a day if compression is good.

Run some marvel mystery oil through the fuel every few tanks to keep valves from sticking.

Expect a smoother but slower flight, and 6-7 gallons per hour. Way more prone to carburetor icing

Swap the ignition when possible.
 
gitmo234 said:
I just got off the phone with the mechanic that did the last three annuals. ... said the first annual he did was very in-depth, removed the crank. ... I felt pretty confident after talking for about an hour about the various work he's done.
Click to expand...
That's good news. If he has looked inside the case and told you that he saw nothing awful, then its not nearly so imperative that you have a jug pulled for inspection. Good luck with the bores; given the compression numbers you got, the bores are probably OK.
 
gitmo234 said:
So, the more articles I read, the more mechanics I talk to with experience with the O-300 continental, the more I hear the same themes:

The bottom of the engine is rock solid. Shouldnt/wouldnt/dont worry about that.

That particular engine sitting will very likely be fine but not make the standard TBO time, will likely need a top overhaul a few hundred hours earlier

The more you fly these engines the longer they last

Borescope the cylinders and check for cracks in the exhaust valves and call it a day if compression is good.

Run some marvel mystery oil through the fuel every few tanks to keep valves from sticking.

Expect a smoother but slower flight, and 6-7 gallons per hour. Way more prone to carburetor icing

Swap the ignition when possible.
Click to expand...

Who's going to tell him???:rolleyes2::confused::rolleyes2::rolleyes2::dunno:
 
Borescope came back "beautiful". I spoke with another mechanic that works these engines a lot and he concurred it sounded solid.

I ordered then prop be dynamically balanced and I signed the paperwork. She's mine
 
gitmo234 said:
Borescope came back "beautiful". I spoke with another mechanic that works these engines a lot and he concurred it sounded solid.

I ordered then prop be dynamically balanced and I signed the paperwork. She's mine
Click to expand...

Great feeling. Hopefully you share some of your adventures. Congrads again.
 
:D
gitmo234 said:
Borescope came back "beautiful". I spoke with another mechanic that works these engines a lot and he concurred it sounded solid.

I ordered then prop be dynamically balanced and I signed the paperwork. She's mine
Click to expand...

Alright, good job. Now just sign the checks and don't write it down and you'll be a happy owner.
 
airdale said:
Scenario I mentioned the seller had no problem at all. Somewhat surprising, actually, but in the end he wants to sell the airplane and he has a bird in hand. It does probably mean new rings and a full-rich, mineral oil break-in period to seat them.

If the seller won't permit it, then I'd suggest to the OP that he walk or be willing to accept the likelihood of your scenario #2.
Click to expand...

No, you don't ever have to pull the jug off the piston if you don't want to, but even if you do, you can simply reassemble.
 
airdale said:
If the seller won't permit it, then I'd suggest to the OP that he walk or be willing to accept the possibility of your scenario #2.
Click to expand...

FTFY

Anyone who demands to pull a jug would be walkin' away from anything I ever sell because you can put me squarely in the camp of there ain't no way in hell someone will be allowed to pull a cylinder. It's both unnecessary and there is too much other stuff can go wrong and/or be damaged in the process.

It's called a pre-buy evaluation and not a pre-buy open heart surgery for a reason. And, BTW, pre-buy "inspection" it's not...for most A&P's who are wise enough to avoid that term to limit their liability.

If someone insisted on pulling a jug then they won't be buying...simple.
 
gitmo234 said:
Run some marvel mystery oil through the fuel every few tanks to keep valves from sticking.
Click to expand...

Jaybird180 said:
Who's going to tell him???:rolleyes2::confused::rolleyes2::rolleyes2::dunno:
Click to expand...

I'll leave it to someone else to tell him about MMO but when I had my O-300 I found that an auto gas STC and a blend of 3/4 MoGas & 1/4 100LL made the engine very happy. I think gitmo and his engine would be much happier going this route than using MMO...if he can get ethanol free fuel in his area.

Straight 100LL didn't stick valves on mine but it did foul plugs like crazy.

gitmo234 said:
Way more prone to carburetor icing
Click to expand...

Mine wasn't, just as my current O-470 isn't either and it too has that reputation, but each engine is unique.
 
Not a fan of MMO but nothing I saw in that accident report states:

A. That MMO was causal
Or
B. That MMO was found in the fuel...they don't say the fuel was tested, only observed to be "red" and "oily."

Sloppy investigating IMO.

Appears to be a red herring. But if it was MMO one quart in 18 gallons is way over the top!
 
Last edited:
timwinters said:
Not a fan of MMO but nothing I saw in that accident report states:

A. That MMO was causal
Or
B. That MMO was found in the fuel

Appears to be a red herring.
Click to expand...

Serious?

The banner towing airplane was being positioned to another airport. After takeoff, the airplane engine lost power. Unsuitable terrain limited the pilot's options, and he struck a chain link fence during a forced landing. Examination revealed low compression in the engine, with air bypass on all exhaust valves, and evidence of detonation. The airplane had 3 fuel tanks, each of which held 18 gallons, and two of which contained uncontaminated fuel. One tank contained fuel to which Marvel Mystery Oil had been added. The fuel was pink in color and had an oily feel. The FAA reported that they found an empty can of Marvel Mystery Oil in the operator's trash. The recommended ratio for the additive to fuel was 1 part additive to 100 parts fuel. The operator did not have any specific instructions on how or when to add the Marvel Mystery Oil, or what ratio to use. The pilot, chief pilot, and manager all denied adding the substance to the fuel. In addition, the manager reported that he interviewed the maintenance personnel and they denied adding the Marvel Mystery Oil to the fuel.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The improper use of an fuel additive which resulted in a power loss. A factor was the lack of suitable terrain.
 
We were typing at the same time. See my edits

One tank contained fuel to which Marvel Mystery Oil had been added.
Click to expand...

I don't see where it says that. It simply says "an additive."

Again, very sloppy investigating if there's not some other document with more detail.
 
Last edited:
timwinters said:
We were typing at the same time. See my edits
Click to expand...

No worries. The NTSB report is mainly just for gitmo to be aware of before he starts adding mmo to his fuel. I don't know if CTM has a different perspective on fuel additives than Lycoming.
 
timwinters said:
Gitmo,

Sorry if I missed it, where are you located?
Click to expand...

I'm going to be located out of 58M, Cecil County Airport. I live virtually the same driving time from New Castle DE, New Garden Airport PA, Harford County Aiport and Cecl.

As far as fuel additives go... WOW. I've never been a fan of them anyway, so I have no problems skipping this one now.

And to the point about learning... I've learned a TON. I'm glad I was at least able to get consensus from outside mechanics, some of which had a vested interested in the sell, some did not

The maintenance shop at Cecil was almost ready to put an offer in on the bird after they went through the pre-buy report, heard the borescope was good and looked at the logs.

EDIT: ironically this was posted inside an airplane at 30k feet over the midwest
 
Last edited:
Also...the airplane buying process is a hybrid of buying a house, buying a car, and playing slots.
 
gitmo234 said:
Also...the airplane buying process is a hybrid of buying a house, buying a car, and playing slots.
Click to expand...

That's hilarious...and accurate! :)

Unfortunately, it doesn't appear like Ethanol Fee MoGas is available anywhere near this airport. The closest I could find on pure-gas.org is:

Bartville Store & Locker
103 Rosedale Rd, Bartville, PA;

which is about 40 miles up the road. I guess it depends on where exactly you live...sounds like you live near Lewisville or Calvert.
 
Last edited:
Im 5 miles outside oxford PA, about 2 miles across the MD state line. The mileage between those airports is vastly different but traffic and roadway type make them equal travel time.

I'd likely be in New Garden but their tie-downs are the most expensive around and the runway seems to have been built specifically to be in a wind tunnel at all times.

Woods on the left, 30 foot drop on the right, quarry at the end (and god knows how many feet down that is), and town/pavement on approach, all wrapped up on the top of a hill with the runway elevated.

Some of my best and worst landings were there!
 
You must log in or register to reply here.
Back
Top