Peter wrote:
But what is the proper procedure?
Generally what I read is that a PBI should be equal to a 100 hrs check/Annual at least plus some items which can be found in the specific type communities. Mooneys for instance would do a 100 hrs check plus some checks on tanks and main spar/steel cage corrosion which are mostly done in annuals too but not as extensively. But generally, with a 100 hrs check you will catch a lot. Many recommend boroscoping the engine if that is not part of a normal 100hrs check too. The important thing is that it should be a shop who knows the type and who know what to look for. Which, admittedly, is difficult for Jodels even though I would know just the shop, but not at all for an O200. There must be tens of thousands of those around.
I know people who have bought unseen airplanes on the basis of the PBI by trusted people alone. One of them has done so twice and had no problems with both of his purchases.
I also know people (including myself) who have bought without PBI when I knew the airframe / owner very well indeed. I purchased my current plane prior its 100 hrs check which was done by the previous owner as part of the deal and under my supvervision, also worked out well.
In the end you can get burned even when executing due diligence. Or you can end up with a great buy when everyone told you to keep your hands off.
Zorg wrote:
Engine has now about 3500 hours in total, 1550 hours since last major (zero-hour) overhaul in 2001, about 50 hours since new pistons, about 300 hours since last top overhaul.
There’s a quite unbelieveable amount of drama in this thread, Lycoming cam issues discussed in relation to Continental engines, get a lawyer (?!?), OMG somebody worked on their own engine (shock, horror) etc, but this is where it gets a bit tricky in the real world: recommended TBO for an O-200 is 1800 hrs so if you stick new or overhauled cylinders on it, you may end up doing more engine work in a few hundred hours. Or not, many people run the bottom ends longer. The year 2001 for the most recent overhaul is no issue in itself.
An O-200 bottom end doesn’t generally suffer from corrosion issues so if you inspect through the big holes in the bottom of the crankcase and at the mag attachment and see no major corrosion, you will likely be OK with that issue.
The basic issue you’re having right now is that the rings didn’t seat when the previous owner installed 9:1 pistons in the existing cylinders 30 hrs ago, resulting in high oil consumption. Other than that the engine seems to be fine. This is really not rocket science 
I didn’t spot it was a Conti engine…
This might be interesting…
However I don’t think this is purely down to not having seated in the rings properly, reading this
One cylinder exceeds serviceable tolerance limits in bore, others are close
Valves / valve guides exceed tolerance limits
Wrist pin bores (or wrist pins) exceed tolerance limits
That’s why the rings didn’t seat: new pistons & rings were installed in at least partially worn bores.
Given that the bottom end has not caused any issues and that the oil consumption issue has an obvious root cause, I’d probably stick a new or overhauled set of cylinders on it and fly. A roughly $4K investment but depending on how much the OP wants to fly it, and assuming there’s nothing else going on, it would likely fly reliably for 5 or 10 years without issue on the existing bottom end.
A little O-200 Continental has BTW essentially nothing in common with larger six cylinder Continentals. It’s a derivation of the original pre-war A-65 that powered about a zillion Cubs etc, and the O-200s themselves powered lots and lots of C150s for a million years.
Silvaire wrote:
OMG somebody worked on their own engine (shock, horror)
Silvaire,
I know in the US a lot is possible but pulling all 4 cylinders of an engine and putting something else by an owner without proper paperwork and without someone qualified checking the work is quite unheard of in Europe, believe me. And I guess the result speaks for itself, the job was not done the way it should have been and has put the new owner in a severely problematic situation. Frankly I wonder if that was why he sold it in the first place? If he has done something to this engine which caused this problems, then yes, a lawyer might be a very viable way.
Silvaire wrote:
O-200s themselves powered lots and lots of C150s for a million years.
That is why I think it will be fairly easy finding another one whith a better history. But even more so, if a reputable engine shop has worked on this engine up to the time the owner put the cylinders on, they might be able to sort that engine out very professionally too. I agree, if there are 4 workable cylinders put on properly it should work indeed. The abuse an O200 can take is legendary and was necessary on the trainer front…
The engine should never have been pulled from the plane, the solution given the obvious root cause was to order new cylinders and install them. The rings installed 30 hours ago didn’t seat and it needs a top overhaul. That’s all there is to it.
Why would installing new cylinders on a homebuilt require substantial amounts of paid labor or expensive paperwork, anywhere?
How would you account for “Wrist pin bores (or wrist pins) exceed tolerance limits”?
Thanks for the great discussion and advice so far, everybody! I’m grateful to obtain some diverse advice / independent second opinion.
In the meantime, my mechanic has inspected the bottom of the engine, and found no issues with crankshaft, camshaft, and gear. Also no cracks in crankcase. He did find gunk and metal particles in the oil filter, but thought it might be from the cylinders.
He also thoroughly inspected the airframe, and found no structural issues. Just a few minor issues that can be fixed, such as cable tension.
So I’m tending to follow the majority opinion here, that another top overhaul with new (or overhauled-as-new) cylinders and stock pistons might be a good compromise. In that case I would bite the bullet and fix the other non-engine issues, and hopefully finally fly and enjoy it for a few years.
In that regard, does anyone know a good source for Continental cylinders in Europe? Aircraftspruce Europe does not seem to carry the O-200 cylinders which Silvaire referenced. At that price, it might be an attractive option compared to used but overhauled cylinders.
Just quickly regarding the engine works by the previous owner:
The aeroplane is under French “CNRA” registration, which allows the owner / builder to do pretty much everything and self-declare their work. I’m told (and partially experienced during last airworthiness certificate (“CDN”) renewal) that official inspections can be quite lax (read: paper inspection), if the examiner trusts the owner.
This was apparently the case for the previous owner. Judging by some of the astonishing issues I found (and already had fixed) in the last two years, no official examiner physically checked the aeroplane thoroughly in recent history (although there was supposed to be at least one CDN renewal with physical inspection under his ownership).
So to be slightly cheeky, having an airworthiness certificate (“CDN”) does not necessarily seem to mean much under CNRA-reg — not even that the aircraft is in an airworthy general condition. :)
He did find gunk and metal particles in the oil filter, but thought it might be from the cylinders.
You might like to do some “extra due diligence” on the metal particles 
This morning I cut open my oil filter and I can tell you what I would do if I found metal in there……
Peter wrote:
How would you account for “Wrist pin bores (or wrist pins) exceed tolerance limits”?
Hard to say. It’s not clear if they mean the wrist pin bores in the pistons or con rods. If the wrist pin bushings installed in the con rods are worn, then they were likely not replaced when the replacement pistons were installed 30 hrs ago. Whether its the wrist pin bushings or the piston wrist pin bores, they are likely checking the (ground) fit by feel, sliding the pin in the bore and feeling the resistance. That’s a somewhat subjective assessment and all that is going to be rectified now regardless.
It’s pretty obvious to me what’s happened here: the previous owner installed new 9:1 Lycon high performance pistons (including wrist pins and rings) in the hope of getting a few more easy horsepower. This was done without addressing the cylinder bores or any other machine work, only swapping pistons. The rings didn’t seat due to partially worn cylinders. Then the previous owner decided to sell the plane as-is instead of redoing the job. This is a very typical story with buying vehicles, but not that hard to fix. I just had a very similar experience with a motorcycle that is much more difficult to work on than an O-200… cylinders came off immediately after purchase.. now fixed. I didn’t consider throwing the motorcycle away
Having an airworthiness certificate doesn’t mean much in relation to the condition of any old plane. Anybody who has been through it knows they all need sorting out after purchase, it’s part of the process of acquiring them.
