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scotch bright pad vs honing?

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Hey all! umm i just have 1 question, i have a ktm 200xc and i heard some people telling me that when i do a top end and if i have a glaze or shiny spots in my cylinder to get a Scotch-bright-pad and rub it with it. does that acually work? can someone post up some pics or vids of you doing it? i thought it had to be cross patterd from a hone? whats the difference? thanks!

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A scotch pad is the "poor man's" way of doing it, yes. A hone is the "right" way to do it, but as long as you get those nice scuffs in the cylinder to help the rings seat, you'll be ahead either way.

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Not to hijack ktm200xc 457racer's thread, but what color sotch brite pad should be used?

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Be careful if using a ball hone. You can chip the plating at the edges of the ports.

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can someone post some pics of you using the scotch bright pad?

It's pretty easy. Just use WD-40, and go side to side in the cylinder, NOT up and down!

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:banana: Yup, red scotchbrite side-to-side. Unless you have noticeable scoring or grooving, then i'd try and get it honed.

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Interesting article and I don't know if our bikes use chrome rings but I can tell you this:

1) I've been rebuilding 2 stroke top ends since I was 14 (I'm 38 now).

2) I've never had to rebore, deglaze, hone, etc any of them. I just put the new parts in and go on and always have.

3) My bikes have always measured fantastic and like new compression levels after just installing rings and doing nothing else.

4) My current 300 is used strictly as a track day bike and I am a capable rider that runs it very hard keeping up w/ 450s. I buy and consequently burn exactly 5 gallons of race fuel per month mixed at 32:1. My 2.5 year old 300 is still on the original piston and only on it's 3rd set of rings and the compression is fantastic. Never touched that cylinder. In fact I don't even measure ring gap or anything.

5) clean air filters, good jetting, and enough two stroke oil are keys to a long engine life.

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Our bikes do use chrome rings.

Wiseco and KTM both use the same thickness ring but the KTM ring seems to hold tension better. Scuffing up the bore with scotchbrite in a 45 degree manner seems to promote better ring seating and can even be used to revive a worn ring when no replacement is readily available.

Edited by sbest
correction

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http://www.angelfire.com/biz/snwvlly/bikes/dnthone.htm

^here it says chrome rings will not seat without honing the cylinder, what type of rings are stock or wiseco and can you get by with just using a sotch brite pad?

That is a seriously flawed webpage.

If he could quote the SAE papers I'd be interested to read them but he doesn't.

Moveover, he is confused on "overbore" vs "underbore" in the last of his article.

I thought it might just be a typo but he says it twice.

I have re-ringed without deglazing and had the rings not seat on automotive engines. I have deglazed and run the same ring on motorcycle engines when no replacement ring was available.

Regarding what he mentions about removing cylinder ridges (not required on our nikasil cylinders), I have seen piston and top ring damage from it not being done. The ridge was created by a worn ring in a worn piston groove. New rings and pistons or a different make of piston hits that ridge which used to be quite pronounced in the 1960s & 1970s when poor oils, rings, cast iron and low engine temperatures promoted cylinder wear. Cylinders were honed back then to get them parallel again. They would often be worn as much as 0.008" at the top of the cylinder. If you didn't hone it a few thou and remove the ridge at the top, the rings would not last 10k miles before it was smoking again.

Super polished surfaces are fine when they are matched perfectly, but how do you get them to match perfectly? Rings will not seat on a highly polished surface. They need the oil and they need the abrasion. Even today's super honing with deckplates is still counting on this process.

That said, a rough surface is not required. Removing even 0.001" of material is not required. Just getting an angled pattern to bite into the ring and carry some oil onto the contact surface is all that is required. I use Scotchbrite myself, because it is non-damaging and removes minimal material which is what you want on the nikasil cylinders. I use my hone on the cast iron sleeves in older 2-strokes, which need a bit more removed to true up the cylinder.

Just slapping a ring in a nikasil bore will work. I have done it when pressed and cannot recall anything going wrong. To each his own...

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I think most of what you are are talking about applies to cast iron and steel cylinders or sleeves. I remember reading something about it a long time ago with plated aircraft cylinders and don't think scuffing is required on Nikasil plated cylinders. Something to do with the structure of the plating being porous with impregnated silicone carbide that holds the oil and gives the texture that wears the high spots off rings and pistons. I think scuffing will clean up any varnish or other deposits on the cylinder though.

The platting is pretty hard and it is difficult to put much more then a visual scratch in it. If you do manage to put much of a scratch cross hatch into the platting, similar to what would be on a steel or cast iron cylinder, the platting is so hard it will wear the rings excessively. The platting is so hard the scratch will be there for a long time and continue to wear the rings and piston for a long time. The factory scratching, or replated cylinder marks, from the diamond hones are very fine and stay there for a long time.

I still scuff mine with Scotch Brite out of superstition and to clean it.

Also, from what I remember, chrome rings are not compatible with chrome cylinders. Even though "chrome cylinders" are usually nickel.

Gary

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Aparently it is OK to run chrome rings on Nikasil because it is not chrome. Chrome rings are not compatible with chrome cylinders, but Wiseco says nobody uses chrome cylinders on dirt bikes. Here are a couple of interesting quotes from Wiseco here at Thumper Talk. These are in context with Wiseco putting a warning in there piston kits with chrome rings saying not to use with chrome cylinders.

Nikasil and chrome are two completely different things! The only similarity is they are both considered platings. Chrome is, well, CHROME. Nikasil is a trade name for nickel-silicon-carbide. It is a nickel based plating with very fine particles of silicon carbide suspended in it. When it is applied to a cylinder bore, the nickel holds the silicon carbide. Nickel also attracts oil, which is obviously good for lubrication. On a microscopic level, the hard particles stick out from the nickel, and the piston and rings glide upon the particles of silicon carbide. Silicon carbide is EXTREMELY hard, which is why the wear resistance is so high, much longer than traditional cast iron bores, especially in dirty environments like dirt bikes.

The reason we say DO NOT USE IN CHROME BORES is because most of our rings are chrome plated too. You can't run chrome rings on a chrome bore because they are the same materials and galling will occur. It has NOTHING to do with the forging, piston alloy, or skirt. You can run chrome rings in Nikasil because it will not gall. The proof of that is that how many OEM pistons come with chrome rings and Nikasil bores.

Hope that helps!

Chrome is not the same as those other platings. So it's not the same as what you originally said. I don't know why Suzuki calls it chrome. You would have to check with Suzuki to 100% confirm, but as far as we know, it is SCEM, not chrome, which ARE different.

Even though very few (if any) motorcycles use chrome bores, we still put that in our instructions as a safety measure. Wiseco makes pistons for many different applications; motorcycles, ATV's, snowmobile, jet ski's, boat motors, etc. Our rings cross over to many applications, some of which do have chrome bores, in addition to cast iron or Nikasil. Hope that helps. :banana:

Gary

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Egad, did I goof up.

I just installed a Wiseco ring today and it was definitely chrome.

I don't know what I had on my mind but I hang my head in embarrassment...

Simple ring job on my 125 did not go well.

Took many more hours than intended but is finished.

High miles and high RPM induced a small crack in the piston as well as highly polished and undersized skirts. It was due. Small end roller bearing was so worn the roller pins fell out. One I could not account for. I searched under the bike, the skid plate, probed with a magnet, took off the water pump, but not found. Wasn't risking new parts to an errant roller pin, so I assembled the engine with the worse parts I had and ran it. No problem. I had a rag over the crank and water ports so I was pretty confident all was well, but I had to check since I couldn't find the pin. Tore it apart and started over again. There were more issues, but it is done. I did scuff it up with scotchbright, slave to fashion that I am.

The only chrome cylinders that I remember are a 1970's 440 Skidoo TNT that I had. I do remember the Chevy Vega with its etched silicon aluminum cylinders, and oddest of all the Briggs & Stratton aluminum cylinder with chrome rings. How does that work?

Nikasil is such an improvement over the old iron liners. Even in snowmobiles in a no dust environment there were always worn, always had to go oversize. We have it good.

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