Honing a Shihl Cylinder. What's the proper grit?

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You guys are right that whoever honed the cylinder I have was a more than a tad over zealous. It looked to me like they tried to hone off the last of the aluminum transfer, instead of sanding it off by hand. Brad, the cylinders you did look great, but do you think you actually get a better ring seal than if you just cleaned them up with the standard (low risk) acid, sandpaper, scotchbrite routine? Or are they just prettier? You and many others here know how to hone a cylinder without trashing it, but some do not.
 
Brad, if I remember correctly you said you routinely use ball hones for your honing. Right? Can you tell us what grit you would use for lightly to medium scratched cylinders? Type of oil etc. Typical rpm's and elapsed time in an average cylinder.

your pics are so fantastic, the cylinders look new!

There seem to be so many folks who don't know much about honing, a good video would be worth several thousand words!

So brad would you consider maybe making a video so that many of the folks on this site might learn the do's and don'ts. If so, they are easy and free to upload to YouTube. Is that something you might consider?

Without a good video I'm afraid that many of us will still not know how to do it properly!
 
You guys are right that whoever honed the cylinder I have was a more than a tad over zealous. It looked to me like they tried to hone off the last of the aluminum transfer, instead of sanding it off by hand. Brad, the cylinders you did look great, but do you think you actually get a better ring seal than if you just cleaned them up with the standard (low risk) acid, sandpaper, scotchbrite routine? Or are they just prettier? You and many others here know how to hone a cylinder without trashing it, but some do not.

Better? Who knows. It's just another tool in the arsenal that I use when needed. I pretty much only use them as the final step in the process of salvaging a cylinder.
 
Brad, if I remember correctly you said you routinely use ball hones for your honing. Right? Can you tell us what grit you would use for lightly to medium scratched cylinders? Type of oil etc. Typical rpm's and elapsed time in an average cylinder.

your pics are so fantastic, the cylinders look new!

There seem to be so many folks who don't know much about honing, a good video would be worth several thousand words!

So brad would you consider maybe making a video so that many of the folks on this site might learn the do's and don'ts. If so, they are easy and free to upload to YouTube. Is that something you might consider?

Without a good video I'm afraid that many of us will still not know how to do it properly!

I only use them when salvaging a cylinder that was scored. I know of one or two sponsors here that hone every cylinder the port. Obviously, they're not destroying your engines. It's in knowing how to use the tool. I remove all, or nearly all transfer by hand using Muratic acid and sandpaper. I also use my die grinder with a cylinder head porting tool that uses green pad and red pad type material to polish the NiSi clean. The last step is to hone it. It puts a nice consistent even finish on the entire bore. I do have a MS310 cylinder that I'll be trying to clean up in the next few days. Perhaps I can video the process.
 
Better? Who knows. It's just another tool in the arsenal that I use when needed. I pretty much only use them as the final step in the process of salvaging a cylinder.

I can appreciate that. I guess my point in all of this is that rookies with ball hones are a bad idea.
 
This is the result of a properly honed cylinder. The remain scratches cannot be felt. No bare port edges here.
IMG8048-M.jpg


IMG8046-M.jpg


Here's another.
4404-M.jpg


This one did not clean up as nicely. Since it's below the port, it's still perfectly useable.
1178440842_ieze6-M.jpg


1178440926_EvYcM-M.jpg

So are these "scratches" what you were aiming for? Or just collatteral damage because you didn't want to waste any time removine the
pasted on aluminum?

This thread kind of goes against all earlier responses.
 
I don't think he is saying that at all Fish.
I think he is simply saying that it won't immediately trash a cylinder beyond repair if done judiciously.
I totally agree with that but just haven't seen a situation where honing was absolutely necessary.


Mike
 
honing

just buy a new cylinder if you hone it you'll probably mess it up so dont waste your time
 
OP here, just filling in some requested details.

In the particular situation I am working on, I have a saw with 100psi cold compression, which runs ok wide open, and will not idle, nor start easily.

Plug fouls often, though mixture is right.

Upon inspecting the piston and cylinder, there are moderate scratches in both.

IMHO, I don't think that the cylinder is ready for the junk pile. it seems likely that if we can carefully remove those cylinder scratches, and add a new piston and ring, we have a good chance of getting back to something closer to 150psi.

There is no way I'm going to reassemble without removing those scratches, and I don't think anyone would recommend it.

That leaves my choice between trying to hand sand those scratches with some 220 paper, followed by some 400, or the seemingly controversial flat stone hone or ball hone for some super light honing. If we could get away with removing maybe a half a thousandth that would seem ideal, as most cylinder specs I've seen are +- a few thousandths anyway. Any plating is typically going to be 3-4 thousandths at least, so that plating remains intact.

I just don't anticipate a new ring seating well against a cylinder without some light honing. I'm also interested in some light deglazing. I understand that a lot of guys use scotchbrite, and that could be an option - though I've not tried it. Honing makes sense to me because you can do as little as you feel you need, and you are assured that you will have a consistent cylinder wall finish - fully around the circumference of the cylinder, as long as there's a light touch.

Hand sanding will be typically concentrated in one spot, and that makes less sense to me than a light, but even treatment with a hone in careful hands.

As I mentioned earlier a certain microscopic roughness in the wall is what is specified by most 2 cycle manufacturers. Most firms finish the cylinder with a diamond hone at the factory and all I've seen, leave intentional fine or microscopic roughness when they are done. All saw manufacturers even have roughness ratings within their factory specs! A highly polished, completely smooth bore, free of ultra fine scratches or ridges is not something I have seen on 2 cycle saws fresh from the factory.

If anyone want to know more about roughness specs I can provide a link to some tech info from Sunnen. They are the company which knows more about cylinder bores and specs than any company in the USA.

Regarding seized pistons and cylinders that seems an easier call. In my experience I would either try to lightly hone the cylinder provided that you can remain within the bore specs, or I'd replace the cylinder, if a replacement was available.
 
just buy a new cylinder if you hone it you'll probably mess it up so dont waste your time

On some saws just buying a new cylinder isn't an option as they are NLA. In other cases the part may cost more than the saw would be worth when the job is done. If done carefully a light honing could be the difference between a running saw or a parts saw.

Not true. Didn't we just go through all this?

Yes we did and it has been stressed that it is a last resort and less is more, by you, as well.
 

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