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Discussion Starter #21 (Edited)
What a head scratcher...

Everything appears in excellent shape under magnifying glass nothing jumps out. The cylinder, piston, and rings all look it great shape as if just installed recently. We took it apart to inspect the rings that are all over the place with no markings as to which side should be up and no inner bevels on them. The serial number says it a wiseco piston but the rings don't follow their description. The oil ring appears to be correct and the others are staggered but not in ideal positions. Could it be as simple as the openings not facing the exact suggested positions?

If the problem is else where all that is left is the oil return from the head is clogged causing it to spill into the cylinder, or the valve seals.... I should add that even though the oil level is low, the engine stud that the oil travels back down the head is full of oil. This make me wonder if there might be a clog at the bottom of the engine not allowing oil to return. As a result the oil being pumped to the head has no where to go but above the piston to burn off.

Then again it looks like the oil path down might be the cam chain. So ....blue smoke is still elusive unless it's the rings.

Thoughts any one?
 

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Hey there,

Justva question as I think through this. Can you still see the hone marks in the cylinder?
 
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Discussion Starter #23 (Edited)
Yep. More so on the sides. There is some light wear on the front and back sides of the cylinder and piston. Enough to smooth the lathing marks in the piston.

I think the rings may have been installed in the wrong order or upside down down drawing oil into the cylinder. Either way they are likely worn in wrong and we'll need new rings. We plan to remove the other rings (only looked at one closely) for closer inspection.
 

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If you decide to do the rings keep in mind wearing them into an already worn, slightly out of round cylinder (even a few 10 thousandths) takes a bit longer than if all was new and perfect. I would very lightly hone the cylinder so that the glaze is broken. One of those hones (read up on the correct grit for this) with all the little balls on the ends of wires that you spin in a hand drill is a good choice for that as they are better fitting to a worn cylinder. Keep in mind to gauge your up and down strokes to get the proper cross hatch pattern in the honing marks when honing. Most of all you need to just lightly brush the surface, just breaking the glaze and just giving a slight cross hatch to help break the rings in. They will not break into a glazed cylinder easy. Then run it hard, especially on deceleration, i.e. WOT, then close throttle to develop as much engine break as you can, do this a lot until you feel it's seated.

One of the reasons you have to be so carefull reinstalling old rings is you need to get them back on the piston and it back in the cylinder without throwing the worn egg shapes out of alignment. If you ever slide your cylinder off your piston in the future on a good working engine don't let the rings spin on the piston, mark them with a marker so if they do spin you can put them back where they were so they have a better chance of falling back into the place they wore into. And always put the piston back on the same way if you pulled the wrist pin.

One other thing I'd like to add is you can not tell if valve stem seals are shot without taking them off and looking inside them and if you do you may as well replace them anyway. If they are hard on the seal surface and the little lips are worn at all they are shot. Generally they don't cause heavy blue smoke at riding speed (they might) unless they are way far gone (but smoking on start up that dissipates is very common. I would replace them anyway as you are in this deep.

Best of luck, post a blow up of the top end it will help us help you.
 

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Discussion Starter #25 (Edited)
I haven't been at it lately with the heat...

Wouldn't the ball types limit you from the ends? I would think they could hook and tear things up. I would have thought the expanding nature of the stone version would work well as long as you don't operate it too fast. Plus they are adjustable, and the ball version you'd need a specific size....I have a 66.5mm bore and have yet find a ball type the right size. Stones..no prob.

https://www.amazon.ca/67mm-Flex-Hone-Cylinder-Silicon-Carbide/dp/B002N36MOA/ref=sr_1_cc_2?s=aps&ie=UTF8&qid=1530791725&sr=1-2-catcorr&keywords=2+5%2F8%22+cylinder+ball+hone

This is a 240 grit. I found an 80 grit but that just sounds nasty.
 

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I haven't been at it lately with the heat...

Wouldn't the ball types limit you from the ends? I would think they could hook and tear things up. I would have thought the expanding nature of the stone version would work well as long as you don't operate it too fast. Plus they are adjustable, and the ball version you'd need a specific size....I have a 66.5mm bore and have yet find a ball type the right size. Stones..no prob.

https://www.amazon.ca/67mm-Flex-Hone-Cylinder-Silicon-Carbide/dp/B002N36MOA/ref=sr_1_cc_2?s=aps&ie=UTF8&qid=1530791725&sr=1-2-catcorr&keywords=2+5/8"+cylinder+ball+hone

This is a 240 grit. I found an 80 grit but that just sounds nasty.
Used cylinders are worn and not true. Using stones which are flat and true will leave areas glazed when when trying to deglaze them causing you to hone more, I.e. Over hone to get those spots. That's why they make ball hones and why you will find them used by people who rebuild regularly. They do a better job on a used cylinder without taking of more material than needed, something you don't want to do on a used cylinder that is already worn. By all means stones are fine on a new bore. You could use stones, just don't over do it. As far as size in balls hones, there is a chart. A little bigger is ok, so is smaller as long as it touches you get it scuffed.

It seems scary the first time but it's quick, easy and does not tear up the edges, even on the bottom.

 
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Discussion Starter #27
Ha...I just watched same video 10 seconds ago.

Oh I hadn't thought about the length of the cylinder just the radius...that would be a concern using stones.
 

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Balls are the way to go on a used cylinder to deglaze. However for many years before they made them I used stones. You just need to pay attention and use care. Using balls is generally a no think in out and done process.
 
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Discussion Starter #29 (Edited)
I had a quick look at the cylinder and it is glazed 360. The only visible hatching is at the bottom. I'm still pushing for the flex-hone but it's single purpose and higher price make it a hard sell.

I just ordered another top end gasket kit, flywheel puller, piston rings, and threw in a clutch removal tool and 54 tooth sprocket for ATV tire on the TW.

Next I'm leaning towards this....I believe it's the right one.https://www.amazon.ca/67mm-Flex-Hone-Cylinder-Silicon-Carbide/dp/B002N36MOA/ref=sr_1_cc_2?s=aps&ie=UTF8&qid=1530791725&sr=1-2-catcorr&keywords=2+5%2F8%22+cylinder+ball+hone

I'm also looking into the valve seals but since it's only issues appear to be oil burning (lots of power, run smooth) it's only because we have the new seals and would offer some peace of mind to know that's done.
 

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Even after thousands of miles you can usually still see the remnants of honing marks, at least on the sides of the cylinder (you want too see it). Front and back of the cylinder wear quicker. I thought you had said this was recently rebuilt? Maybe before buying rings, hone etc. you could have it measured at a shop? I'm concerned that the bore is more worn than you think it is considering you say you really can't see too much of the honing marks. Keep in mind oil hangs out (should hang out) in the bottom of hone lines to help lubricate the rings, reducing wear on them and the cylinder, its initially rough and it's that roughness that wears (seats) the rings in. Once the rough area wears away the bottom of the hone scratches are supposed to hold a very little bit of oil. You can have a glazed cylinder and still see remnants of the hone, seeing the hone marks indicates a cylinder in decent condition but you want to re hone if changing rings anyway (to wear - aka seat them in.

If measured and it's in spec then order parts and hone. Or you could chance it. I can generally tell by looking at a cylinder, but that's only after seeing probably over a hundred or more if I could get away with a hone job. It's not a huge investment to chance it but if you have someone close by that can measure it all the better.
 

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Discussion Starter #31
I tried getting a picture but it won't reveal much. Under magnification (reading glasses) you can see the oil's wavering shiny surface over partially glazed cross hatching. It's still there enough to look somewhat recent but worn down with some vertical micro scratches. I don't think it's worn enough to throw off spec but enough to warrant a honing for a quicker break in. I'd caliper it but the head is still partially assembled and not mine to work on alone. Plus I already ordered the rings but I think it will work out fine.
 

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I'm also looking into the valve seals but since it's only issues appear to be oil burning (lots of power, run smooth) it's only because we have the new seals and would offer some peace of mind to know that's done.
Depending on the design of the head in the area of the valve stem seals and where oil lays and flows around them it could be those seals causing the issue. I'm not familiar with that head but valve stem seals can cause oil burning during normal running conditions even after initial start up if they are generally covered with oil or the design lets oil pool around them. They do need to be ruled out / eliminated as a possible contributor to the cause.
 

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I tried getting a picture but it won't reveal much. Under magnification (reading glasses) you can see the oil's wavering shiny surface over partially glazed cross hatching. It's still there enough to look somewhat recent but worn down with some vertical micro scratches. I don't think it's worn enough to throw off spec but enough to warrant a honing for a quicker break in. I'd caliper it but the head is still partially assembled and not mine to work on alone. Plus I already ordered the rings but I think it will work out fine.
Nice, if you can still see remnants of the last hone you should be ok if the last hone was after a re bore and not just a re ring and hone job.

You have an internal t mic? Nice ;)

Adding.. you really need a fresh hone when putting in new rings, it's not just for a faster break in. It's just that they are very unlikely to break in without a fresh hone.
 

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Discussion Starter #34 (Edited)
The PO had the front drum cable spring missing, the clutch lever angled way too high, back brake barely worked. A few basic tweaks and things worked much better so it appears he didn't know what he was doing. I doubt it was honed since it was bored. I don't even think the head was cleaned properly during the bore....there was still crud caked outside the top cylinder gasket from the last blow out. Who really knows. How often does anyone fully disclose what a bike has been through. Out of 6 deals I witnessed only one.

What is an internal t mic?
 

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Ah....got ya. Nope just digital calipers.

What about grit size? 220- 280? I found a variety of 2 5/8" for my <67mm cylinder on ebay.
https://www.ebay.ca/itm/2-5-8-Nikasil-Cylinder-Engine-FlexHone-Flex-Hone-240-grit-Aluminum-Oxide-/352371016727?hash=item520af30417
I would call them, the manufacturer, I did when I got mine, which I just searched for so I could tell you the grit but there is no tag on it. They were great last I called them. If you get the right size you can use it in your tw in the future. They asked the use (re-hone for rings), the cylinder material (steel, non lined in my case) and the diameter and depth of the hole. Once they had that they gave me a part number.
 
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Ps... do you actually have a nikasil lined cylinder? You linked to one that's for a lined cylinder. Those generally don't get rebored to often.
 
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Listing ended, guess you bought it..?
 
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Discussion Starter #40 (Edited)
Geesh...I'm glad I didn't. but I see there are also hones made with silicon carbide. I doubt it's coated as it's been bored out 1mm. I'm pretty sure it's the stock sleeve in the cylinder.

For something seemingly so simple it just gets more and more complicated. More research.....

this one claims to be compatible with XR200r 2000 not my TW though Oh well...https://www.ebay.com/itm/Flex-Hone-Cylinder-Ball-Hone-65-67mm-for-Motorcycle/253702670868?fits=Model%3AXR200R&epid=1745488468&hash=item3b11db8a14:g:iV0AAOSw0O9bK8QP
 
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