A friend of mine gave me an OS .46AX for evaluation. After removing the head, I noticed that the plating on the cylinder was about 50% peeled.

    WHY OH WHY did you TAKE IT APART!?  Particularly in the light of:

engine started instantly both hot and cold with a quick bump with an electric starter.  It ran perfectly at high speed and idle.

      Which tells you what?  It tells you that if you had done NOTHING to the engine, you would have been perfectly OK with it, at least for now. Now you have an engine that has been idly disassembled and reassembled, and are neurosing over something that apparently makes no difference.

    If it runs OK then it is obviously irrelevant whether it is "peeled" or not peeled. It might wear out someday, otherwise, it might run fine for you for the next 10 years. Most of my OS engines have never been apart, so I actually have no idea whether any of them are "peeled" or not peeled. The few I have worn out, the liner was OK, but the point is that it was worn out, not what happened to be or not be on the liner.

   Don't take engines apart unless you have to, ever. If something goes wrong, then, that's another matter, but even after you disassembled and reassembled it, this one works OK, so by definition, *nothing has gone wrong*. Disassembling it for "inspection" (and presumably "fixing" it if it fails inspection, which is really what you are asking about) seems a little over the top.

   My suggestion in this case - don't remove the carb, don't put on a venturi, put your tools away, rig it to work at partial throttle to adjust the speed, and then just fly it, don't "inspect" the insides, and only touch it with a tool if it won't run any more.

    Brett
   

      Hello Brett:

      WOW chill Dude!,  I do not consider removing the head on one of these engines as taking apart!  I doubt that anything destructive could,would have happened to the engine.  If you know of any damage that may be caused by removing the head, kindly share this knowledge.

     Again, I am not trying to pick on you, but how is removing 4 of the 8 (or 6 of 10) of the fasteners that hold the entire engine together not "taking it apart"?  There are dozens of ways to change it by doing that, you could rotate the liner, you could mis-tighten it. And there is already another thread where 8 of the 18 parts in the entire engine were replaced because of improper operation of a screwdriver.

   And in fact, you came on wanting someone to tell you to get a replacement liner, or a "better" one, maybe with "stunt numbers", which means taking it all the way apart and probably modifying it to destruction - and I have seen that over and over and over again, and most of your threads are like that.

    Guys, everyone, not just Frank - unless you *know* there is a problem, or it has been crashed and not cleaned out, *leave it alone*, don't take off the head, backplate, etc. to see what is in it, or whatever.  I see this *incessantly*, why?  You hadn't even run it, much less flown it. If you fly it, experiment for a while, find a problem, diagnose the problem, then need to change something, then yes, fine.

  I am getting frustrated because of the thread after thread after thread where someone pre-emptively disassembles or modifies their engine, then complains that this or that part or engine is "no good", and then start grinding it or doing special tricks with it, and then go down the rathole.

    As always, it's your engine, you can do what you want, no skin off my nose. It's just advice. But when you have problems later, the first question will always be "did you take it apart and/or modify it?", and if so, it will frequently mean that someone else will have to put it back, or you will never get a good engine run.

    In this case, you may have gotten away with it, but that is TBD, since you haven't flown it, and no one knows whether it will ever be a good engine for our purposes. Now, we CAN'T know from this engine, it has been fiddled with, if it has a problem later, it might be due to the fact that it's not a very good engine for CL, or, it might be that this particular engine is somehow not working normally because of this.

    Brett

     

      Hello All:

       Thank you for all of the replies.

       No, I do not idly take engines apart.  I have learned my lesson re. engines and clocks. Lol.

       I forgot about how stupid the masses can be.  Or should I say ignorant?  I also place myself in this category.  Oh yes, aging does not help this process.  I guess that damage is possible by rr a glow plug.  I too have seen that the pin in the crankcase that locates the cylinder, crushed flat under the flange by improper installation.  I also have seen unspeakable crimes against engines due to poor uses of screwdrivers pliers etc.

       Many questions that I have posed on this site concern engines that are not mine.  Most have had incorrect parts installed, damaged parts, and engines that have been ruined by abuse. 

        In any case thanks for the help and stay well.

        Frank




     

I have an OS 61 SF that had countless hours of flying with a liner that was showing the brass (I don't think that it's peeled, just thin) and ran fine right up until the day I buried it after I folded the wing at the bottom of a square (RC) loop. I destroyed the carb, but that was all that was really wrong with it.

That engine has a new carb and a Brian Gardner P&L waiting to go into it and it'll probably do another decade's flying.