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Jeff Redd

Cylinder scored from shop honing. Will she be okay

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14 minutes ago, dirt duchess said:

You can use a ball hone in them.  Will make nice cross hatching without removing a bunch of metal.  I use ball hones in all my plated cylinders, each time I replace a piston and rings.

 

will condition the nikasil nicely and will not alter existing bore size at all.

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Just now, dirt duchess said:

You can use a ball hone in them.  Will make nice cross hatching without removing a bunch of metal.  I use ball hones in all my plated cylinders, each time I replace a piston and rings.

You shouldn't.

Nikasil is a heterogeneous material, like concrete on a much smaller scale.  What makes it hard and wear resistant are the chunks of silicon carbide embedded in the nickel plating.  These little chunks are suspended in the nickel like aggregate in concrete. 

When you hone you are doing two things.  The abrasive hone is not harder than the silicon carbide but it is much harder than the nickel substrate that the silicon carbide is embedded in.  It cannot cut the carbide but it can scour away the nickel and dislodge the chunks of carbide from the cylinder wall.  This is bad.  In addition to that, the abrasive debris from the process embeds loosely into the nickel plating where it breaks free easily and floats around your engine until it is either filtered out or blown out through the exhaust.

I know lots of people still do this, that doesn't mean they should.  Honing should have gone away with cast iron cylinders.  I've never seen a service manual suggest it, I've never done it and I've had great results skipping that step.

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1. A hone goes up and down but turns 360 degrees also which is what gives the cross hatch pattern. Unless the guy was totally lost and just put the hone in the bore and just drug it up and down you won't get vertical lines in the bore.

2. IF the guy you went to knew what he was doing he would have known you cannot hone a YZF250 plated cylinder with a standard Sunnen or equivalent "stone" hone because it would be like sanding a piece of glass. Fine grit glaze breaking / finishing stones will NEVER remove anything from a Nikasil cylinder except whatever is stuck to it that you can remove with your hand, soap and water. Honing is done with a diamond hone because the plating is super hard and stones just don't work. After the guy figured that out he didn't charge you because he literally didn't do anything but highly polish your plating to clearly reveal the vertical scratches that were already there as said by other members. What he did was like super cleaning the surface to reveal what was already there.

3. 76xtdrvr already told you what to do with the cylinder and how to do it. I understand it's two separate bikes here but your basically riding on borrowed time with both of them ( valves in one and cylinder on the other ). Honestly if you cannot feel the scratches it's just cosmetic, like another member said unless the coating is flaking off it doesn't really wear it just chips off. Unless you had some engine failure that dimpled in the coating but didn't chip it off you should be good to go.

4. Here's where I had a few cylinders re-plated a few years back I believe recommended by Eric Gorr  - https://www.millennium-tech.net/serviceInfo.php?id=7

5. Why would you lap a valve to a seat and then use a different valve? If you understand the concept of lapping in a valve you are mating the two surfaces together ( the valve face and the valve seat ) for a pretty much perfect seal. Why would you switch the valve? Now it's not a match set any longer. If they are showing noticeable wear BY EYE valve and most likely seat are already worn out which means lash is out so they need replacement AND the head needs a valve job and obviously valves need reset. Quick check is spray some brake clean or enough alcohol into the port to cover back side of valve when the springs are on and if it leaks through your done. A single leaky valve on a one cylinder engine and it's game over. I did a head on a DRZ 450 the way the guy wanted it done and it lasted about a week.  If they are titanium valves save up and get new and do it right. It all seemed like a 1 shot deal valvetrain.

 

 

 

1. A hone goes up and down but turns 360 degrees also which is what gives the cross hatch pattern. Unless the guy was totally lost and just put the hone in the bore and just drug it up and down you won't get vertical lines in the bore.

2. IF the guy you went to knew what he was doing he would have known you cannot hone a YZF250 plated cylinder with a standard Sunnen or equivalent "stone" hone because it would be like sanding a piece of glass. Fine grit glaze breaking / finishing stones will NEVER remove anything from a Nikasil cylinder except whatever is stuck to it that you can remove with your hand, soap and water. Honing is done with a diamond hone because the plating is super hard and stones just don't work. After the guy figured that out he didn't charge you because he literally didn't do anything but highly polish your plating to clearly reveal the vertical scratches that were already there as said by other members. What he did was like super cleaning the surface to reveal what was already there.

3. 76xtdrvr already told you what to do with the cylinder and how to do it. I understand it's two separate bikes here but your basically riding on borrowed time with both of them ( valves in one and cylinder on the other ). Honestly if you cannot feel the scratches it's just cosmetic, like another member said unless the coating is flaking off it doesn't really wear it just chips off. Unless you had some engine failure that dimpled in the coating but didn't chip it off you should be good to go.

4. Here's where I had a few cylinders re-plated a few years back I believe recommended by Eric Gorr  - https://www.millennium-tech.net/serviceInfo.php?id=7

5. Why would you lap a valve to a seat and then use a different valve? If you understand the concept of lapping in a valve you are mating the two surfaces together ( the valve face and the valve seat ) for a pretty much perfect seal. Why would you switch the valve? Now it's not a match set any longer. If they are showing noticeable wear BY EYE valve and most likely seat are already worn out which means lash is out so they need replacement AND the head needs a valve job and obviously valves need reset. Quick check is spray some brake clean or enough alcohol into the port to cover back side of valve when the springs are on and if it leaks through your done. A single leaky valve on a one cylinder engine and it's game over. I did a head on a DRZ 450 the way the guy wanted it done and it lasted about a week.  If they are titanium valves save up and get new and do it right. It all seemed like a 1 shot deal valvetrain.

 

 

 

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2 minutes ago, BrianPaul69 said:

1. A hone goes up and down but turns 360 degrees also which is what gives the cross hatch pattern. Unless the guy was totally lost and just put the hone in the bore and just drug it up and down you won't get vertical lines in the bore.

2. IF the guy you went to knew what he was doing he would have known you cannot hone a YZF250 plated cylinder with a standard Sunnen or equivalent "stone" hone because it would be like sanding a piece of glass. Fine grit glaze breaking / finishing stones will NEVER remove anything from a Nikasil cylinder except whatever is stuck to it that you can remove with your hand, soap and water. Honing is done with a diamond hone because the plating is super hard and stones just don't work. After the guy figured that out he didn't charge you because he literally didn't do anything but highly polish your plating to clearly reveal the vertical scratches that were already there as said by other members. What he did was like super cleaning the surface to reveal what was already there.

3. 76xtdrvr already told you what to do with the cylinder and how to do it. I understand it's two separate bikes here but your basically riding on borrowed time with both of them ( valves in one and cylinder on the other ). Honestly if you cannot feel the scratches it's just cosmetic, like another member said unless the coating is flaking off it doesn't really wear it just chips off. Unless you had some engine failure that dimpled in the coating but didn't chip it off you should be good to go.

4. Here's where I had a few cylinders re-plated a few years back I believe recommended by Eric Gorr  - https://www.millennium-tech.net/serviceInfo.php?id=7

5. Why would you lap a valve to a seat and then use a different valve? If you understand the concept of lapping in a valve you are mating the two surfaces together ( the valve face and the valve seat ) for a pretty much perfect seal. Why would you switch the valve? Now it's not a match set any longer. If they are showing noticeable wear BY EYE valve and most likely seat are already worn out which means lash is out so they need replacement AND the head needs a valve job and obviously valves need reset. Quick check is spray some brake clean or enough alcohol into the port to cover back side of valve when the springs are on and if it leaks through your done. A single leaky valve on a one cylinder engine and it's game over. I did a head on a DRZ 450 the way the guy wanted it done and it lasted about a week.  If they are titanium valves save up and get new and do it right. It all seemed like a 1 shot deal valvetrain.

 

 

 

I did the lapping just for the seat because there was a small issue and when I researched it was fine to do it with a spare valve, either way the rmz ran &%$#@!ing perfect after ward with amazing compression whereas before it had low comp and ran like junk. Just because something isnt recommended doesnt mean that if you know what you're doing you cant do certain things to improve them... 

 2, as I said with the cylinder. I brought in said so what they thought best whether it be boring, sleeving or honing. They chose to hone. All I was asking her is other opinions on if I can run it. Not what I shouldn't do or should do with it were past that point.

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Posted (edited)
38 minutes ago, dirt duchess said:

You can use a ball hone in them.  Will make nice cross hatching without removing a bunch of metal.  I use ball hones in all my plated cylinders, each time I replace a piston and rings.

I'm not sure where you got this info but I would NEVER ball hone anything but an old pipe maybe. The only thing that will do anything to a plated cylinder is a diamond hone. With a piston that short the clearance it critical and if it starts to rock the high RPM will bring it to pieces pretty fast. Again nothing but a diamond hone will touch the plating but if you really want to have some fun put a ball hone in a 2 stroke cylinder and spin it really fast :) About all its good for... 

Edited by BrianPaul69
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As far as lapping the rmz with the spare valve this is NOT the first or even 2nd time I've done this the last bike I did it too, put over 50 hours on it after ward's with zero issues. Until I sold the bike the guy is still riding it to this day on the same valves with the lapped seats..

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49 minutes ago, dirt duchess said:

You can use a ball hone in them.  Will make nice cross hatching without removing a bunch of metal.  I use ball hones in all my plated cylinders, each time I replace a piston and rings.

You can but its really not a good idea 

They need a diamond hone.

That's still shit though

2 step plateau honning with a diamond hone is proper.

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9 minutes ago, BrianPaul69 said:

ANY respectable engine building shop will not have a ball hone ANYWHERE on the premises. Any respectable engine builder will know why.

hahaha is that right?  

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Also ... I'm eating up data on this post like a 4 year old in Romper Room.

In my downloaded KX 100 Owners manual "scores in cylinder wall should be smoothed with #400 to #600 Emery Cloth" have you tried that to rid marks?

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4 hours ago, Jeff Redd said:

Dropped this cylinder off to get honed. The shop put scores in it. They claimed they were already there but decided not to charge me....🙄 anyways the guy said the bike will probably not run and IF it does its gunna burn a quart an hour. I cant feel these at all my nail doesnt catch I can not feel only see them.received_307580500416560.thumb.jpeg.1f521e2458a83ae4046a502a82d555fb.jpeg

For some reason threads like this about cylinder prep always seem to turn into arguing about what works and what doesnt and everyone has their own opinion as to whats best. The pic you posted might not show the surface finish very well because of lighting or angle etc but if those vertical marks cant be felt with a fingernail or a pointed oring tool they wont be problem.

In general if a piston and/or rings are being replaced usually some type of prep is a good thing but, beyond that it really depends on the condition of the cyl surface as far as what might be the best thing to do. Some engine cylinders may only need to be cleaned, while some may need to be honed, and some may need to be replated based on how much wear, hours or damage the cylinder wall has. 

Also seems to be some confusion about cleaning and honing. Using a scotch brite pad and some elbow grease would be an attempt at cleaning a cylinder and may work just fine in a cylinder thats in great condition.

Does a brush hone or flex hone just clean or does it also lightly hone the cylinder? Depending on the size of the hone, material its made out of and grit it can do both to a degree. Something that needs to be mentioned also is that often times a cylinder  gets prepped to restore or get the RA (roughness average) back to an effective level so new rings will seal well and the cyl wall will hold a very thin oil film. Often times cylinders with plenty of hours will have areas where it is smooth and the RA needs to be restored. 

Replate or replacement would be needed if the cylinder is damaged.

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9 minutes ago, Rod21 said:

Also ... I'm eating up data on this post like a 4 year old in Romper Room.

In my downloaded KX 100 Owners manual "scores in cylinder wall should be smoothed with #400 to #600 Emery Cloth" have you tried that to rid marks?

I have not, it hasn't been suggested and is not something I'd have thought of I will give it a try, thank you the advice!! That's what i was looking for with this post. Not what I've gotten lol.

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1 hour ago, turbo dan said:

You shouldn't.

Nikasil is a heterogeneous material, like concrete on a much smaller scale.  What makes it hard and wear resistant are the chunks of silicon carbide embedded in the nickel plating.  These little chunks are suspended in the nickel like aggregate in concrete. 

When you hone you are doing two things.  The abrasive hone is not harder than the silicon carbide but it is much harder than the nickel substrate that the silicon carbide is embedded in.  It cannot cut the carbide but it can scour away the nickel and dislodge the chunks of carbide from the cylinder wall.  This is bad.  In addition to that, the abrasive debris from the process embeds loosely into the nickel plating where it breaks free easily and floats around your engine until it is either filtered out or blown out through the exhaust.

I know lots of people still do this, that doesn't mean they should.  Honing should have gone away with cast iron cylinders.  I've never seen a service manual suggest it, I've never done it and I've had great results skipping that step.

Turbo Dan on point...

In the know

Unfortunately you can lead a horse to water but you can't make them drink....

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30 minutes ago, Jeff Redd said:

I have not, it hasn't been suggested and is not something I'd have thought of I will give it a try, thank you the advice!! That's what i was looking for with this post. Not what I've gotten lol.

I'm pretty sure using emery cloth to remove scratches in a cylinder bore would only be for an unplated (cast iron) cylinder, so make sure you're not talking about using emery on a chrome plated bore. To use emery cloth on a chrome bore would be the same mistake as honing one would be.

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2 hours ago, turbo dan said:

You shouldn't.

Nikasil is a heterogeneous material, like concrete on a much smaller scale.  What makes it hard and wear resistant are the chunks of silicon carbide embedded in the nickel plating.  These little chunks are suspended in the nickel like aggregate in concrete. 

When you hone you are doing two things.  The abrasive hone is not harder than the silicon carbide but it is much harder than the nickel substrate that the silicon carbide is embedded in.  It cannot cut the carbide but it can scour away the nickel and dislodge the chunks of carbide from the cylinder wall.  This is bad.  In addition to that, the abrasive debris from the process embeds loosely into the nickel plating where it breaks free easily and floats around your engine until it is either filtered out or blown out through the exhaust.

I know lots of people still do this, that doesn't mean they should.  Honing should have gone away with cast iron cylinders.  I've never seen a service manual suggest it, I've never done it and I've had great results skipping that step.

What if anything do you use to prep a cylinder?

There are many people that have and do use brush hones with great succcess and havent heard of any issues caused by using the correct brush hone. 

 

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42 minutes ago, kachow said:

I'm pretty sure using emery cloth to remove scratches in a cylinder bore would only be for an unplated (cast iron) cylinder, so make sure you're not talking about using emery on a chrome plated bore. To use emery cloth on a chrome bore would be the same mistake as honing one would be.

Not really, 400-600 is only going to remove external imperfections...I wouldn't go Conan on one area for too long and use plenty of oil.

At the end of day ... if everything mics good and compression is within specs, it's all good.

 

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1 hour ago, kachow said:

I'm pretty sure using emery cloth to remove scratches in a cylinder bore would only be for an unplated (cast iron) cylinder, so make sure you're not talking about using emery on a chrome plated bore. To use emery cloth on a chrome bore would be the same mistake as honing one would be.

Incorrect ... the peeps that designed the machine AKA as engineers have given stringent guidelines on how to maintain the machine they built. 

What you read on the internet or talk amongst your buddies is a moot point. 

Sure some aftermarket companies have exceed or bettered OEM components especially in race world, but you can't go wrong with starting with the basics, especially with an engine refurbish.

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