Ouch!

It would depend greatly on exactly what the "burr" looks like and how it got there. If it is entirely in the window, and has not disturbed the bore, then I would try in this order of preference: X-acto, Swiss needle file(s), slipstone, and only as a very last resort a Dremel with a stone.

On some chromed liners, there would be chrome "nuggets" left in the windows that might break off and ruin the engine when running. This might be an example of something that needed attention prior to running. I have seen this on a few GZ engines and cleaned up with the X-acto.

If the "burr" was created by a broken ring during assembly/disassembly/running, then it is likely that metal was moved into the bore. Since metal does not compress, a ding in one place guarantees a bump somewhere else. One way to try to check this is to take a gauge pin (or drill blank) and roll it around inside the bore. Roll it over the suspected area. If you can feel any rocking top to bottom then you have a problem. Even if you can't, you may still have a problem.

It would take a lot to convince me that a hone (like a 3-stone spring mounted unit) would take care of a local bump without grinding away material in places you don't want ground away. A hone is not a reshaping tool. It is a "knock down the tool marks" tool. I always worry that an abused--or just well used--hone has stones that are no longer flat. (Not really flat in two axes, but straight along the rotation axis.) Again, you would be taking off material in places that you don't really want to. Making a bore wavy while trying to remove a burr is not an improvement.

If you know someone with a Sunnen hone, who has the tooling and knows how to use it that would seem to be a good prospect. Then find out how much. Likely that custom work is more than a replacement part. The real dilemma here is attempting a rude fix, then running it to see if it all worked out, and then ruining the piston, ring, head, plug and whatever else gets pounded with shrapnel.

It would take a very deft touch with a Dremel to clean up a local spot, but would be better than attempting a hone on the cylinder in my opinion if a significant ding protrudes into the bore. Perhaps best would be an adjustable lap than you could attempt to localize to the area in question. Again, not a great bet. You have the advantage of going slow with a lap.

The old shampoo/conditioner advertisement from way back had it right:  Just Don't Do The Damage In The First Place.

I know, not very helpful after the fact.

Sorry to hear of your troubles,

Dave

            Hi Dave and Dane,

             Thanks for the great replies.  I think that the best remedy for this problem is a new cylinder.  For 26.50, I think that is fair deal.

              Happy new year,

              Frank mccune’

NO hone   is it at the top or bottom of the port ,  if on the bottom not as much care needed. grind through the bur with a fine stone on a Dremel  then one of their bullet shaped rubber polishing thing.and blend it into the rest of the port


do the same for the top of the port with more care. u don't start building until past that point so u probly wont see any diff in performance just make sure u get all the bur and clean with soap and hot water.oil and give it a try


what engine is it

Frank,

Well, if the damage came from a broken ring, and the piston and the rest were already involved, you have little to lose in giving a repair a try. I would.

A couple of further comments:  if you can't see what you are working on, it becomes infinitely harder to achieve what you are after. Lighting is key. And if your eyesight isn't great, a magnifier might help as well. Second, you need both hands for the tool if at all possible; juggling a liner while trying to hold a tool/device may not be optimal. I might change strategies with a Dremel, and try freehand holding. You may find that you try to hold the tool rigid and move the work gently up to it. Definitely a skill operation.

Again, good luck with your repairs,

Dave

I hate to say anything more, I am not the engine police - but this job has gone completely off the rails.

If it were just a burr, just gently burnishing it down with a steel rod and moving ahead would be fine. But this is problem #4 or 5 with this engine, damaged liner, shattered ring, etc.

   Since parts are easily available, I would very strongly suggest just getting a new liner (which was damaged already by the channel lock removal), a new ring, and a new piston (since you have no idea whether the groove was damaged when you broke the ring for whatever reason), putting it back together carefully, and then go break it in. Don't "fix" anything along the way, just take new parts, assemble them gently, and put it back together. And then leave it alone, just run it.

    Do as you wish, of course.

    Brett