Weepy base gasket: And now, a trip to US Chrome :(

[AZRickD]

Poopie !! Double Poopie !!

I dropped off the KDX at MonkeyButtParts at lunch today. It was scheduled get a pretty thorough treatment. Top-end with new Wiseco piston, full chain and sprocket set, new clutch and brake cables, tires and brake pads.

I had a chilling feeling at 3pm when I saw "MonkeyButt" on my cell phone display. I answered, only half-jokingly, "Don't tell me, my cylinder bore is scarred beyond recognition."

Nope. It was corrosion.


They said they had never seen something like that. The moto-shop on the other side of their shared wall said the same thing...



The corrosion went down about 3/4" from the top. It was slightly rough to the touch, not slick like the rest of bore.

While we're at it, here's a pic of the piston...



So, the options are to send it up to one of the two re-plating shops in Wisconsin (US Chrome, or that other one). "That other one" sometimes has an exchange (with core charge), but I have my doubts as to the availability of KDX220 cylinder.

So, it looks like a three-week turnaround (best case). And more money out of my pocket.

I think I need a hug.

Rick

[Indawoods]

Scotch-brite won't clean it up?
Is it through the plating?
Cylinder out of round?

[AZRickD]

Out of round? They haven't measured it yet.

Perhaps Robb will chime in tomorrow.

Scotch Brite? If once-week-riding didn't allow the rings to scrub it off, I don't suppose it is scrubbable.

The question is, what is being corroded? I thought that the niko was not supposed to corrode. If so, is it something underneath the plating that is corroding, meaning that the integrity of the layer has been compromised?

Unless you think it is rust that has been deposited *on top* of that layer instead of coming from underneath it.

Rick

[skipro3]

That's more carbon than I've seen in a long time on that piston. Not bad on the blowby by the rings though. What's the under side of the piston look like?

Here's my .02;

Clean it with scotch brite and some sort of rust remover. check the bore for spec. Check for plating flaking anywhere. that rust is probably just coming through the plating. It's a pretty porous plating from what I've heard in the past. Course texture of the plating is supposed to enhance oil staying on the cylinder walls. Is the plating just completely worn away in that area? Put in a new piston and rings, lightly hone the bore and fire it up. Then check compression. If it's good, then ride it. Afterall, if you end up having to plate it anyway, none of these tasks is going to hurt it any more than it is.

I just wonder who drowned out that bike and left it to rust up? Almost looks like it might have gotten wet through the air filter during a wash, then sat all winter with the piston about in that spot?? I know AZ isn't known for rusting anything, and I don't know when the off season is, but I can't help but think that it is just cosmetic. Measuring will tell the story.

****EDIT****
You know, after looking at that again, I got a brand new barrel from a dealer and that whole bore looked like the top part of your bore. I think it had to do with the manufacturing process. I think CC has seen that brown coloration as well. If so, I hope he chimes in.

[AZRickD]

Interesting comments.

It's nice to at least consider other options.

Real or imagined.

I didn't know to look at the underside of the piston. What should I look for?

Rick

[Green Hornet]

Coolant Leak?????

[Mr. Wibbens]

As easy as it is to do a topend yourself I can't imagine sending it off

[AZRickD]

No evidence of a coolant leak. I've had to top it off once in six months.

As to why I didn't do it myself (your question isn't particularly helpful to my situation and injects your personal bias into my situation).

For example, I could say, "I can't imagine why anyone who works for a living would bother to do it himself when hiring a mechanic to do it is pretty cheap and allows me to spend more time with my family. I'm going to grad school, working full time, coaching youth sports, and preparing my house. I don't have the time."

See what I mean? Who the **** cares?

And, frankly, if I had done it myself, I would have missed the significance of the situation. Stripping the head down for plating requires more time than I can budget towards that activity.

Back on topic. Someone wondered why the top of the piston was so black and asked about the bottom of the piston. I don't know why the top of the piston is black. The plug looks normal. The top of the combustion chamber is literally clean and shiny, as is the bottom inside portion of the piston.

Rick

[skipro3]

I was asking about the under side of the piston because I've heard that if it is dark, like chocolate, that it may be significant. I think it indicates that the incoming charge of air/fuel is burning by touching the hot underside of the piston. That might cause some discoloration of the barrel.

Personally, just from the photos, I don't think there's that much to worry about. If the bore is true and within specs, and the plating is still intact and not worn out, then it's just cosmetic.

I sure wish someone with more experiance would jump on here to offer more advise. I've not seen that many barrels myself and I don't have yours right in front of me to tell if it's really serious or not.

Come on guys, jump in and offer up some advise.

[Mr. Wibbens]

No evidence of a coolant leak yet your base gasket was leaking oil. How do you know it was not leaking coolant inside the cylinder?

[AZRickD]

I don't know for sure...

...but there was no coolant leaking outside (even though there was evidence of pressue differential using the brake cleaner), and I've not had to add any coolant in months. There was no coolant in the cylinder.

Also, automotive coolant has "rust inhibitors." Not the same for moto-coolant?

Skipro, I don't think it's just cosmetic. It is rough to the touch. If it were merely rust being depositied, it would come off with a light touch. My guess is that the lining was breaking down there and the Fe in the liner is corroding.

Rick

[Indawoods]

Let's see...the cylinder is aluminum... the lining is what?
What the heck is rusting? I don't get it!

[AZRickD]

I did a google on KDX +"steel liner" +cylinder

and got many hits.

I'll have to apply a magnet to the bore to see if it is Ferrous or not.

The plating must have thinned out, which is exposing some micro-pin-holes into the liner.

It doesn't have to be a water issue since the products of combustion is CO2, water, (and spooge).

If the plating is that thin, and since it is unevenly distributed, can I really risk that kind of failure, 35 miles into the desert in June?

I think I'm buying piece of mind.

BTW, I've just e-mailed Fredette and Ron to see if they have any cylinders of good repair for sale. It certainly would speed up the turn-around time.

After reading all of the US Chrome horror stories here, what about a re-sleeve?

Rick

[RBD]

I tend to recommend what others have said about using a scotch-bright to clean the cylinder (then a light oil).

The coating on the KDX cylinders have a little iron in them (you can even get a magnet to stick to it a little) and it can get a light rust effect on the cylinder bore (any water moisture). Just as others have said if it has no scars or missing plating, I would not worry.

Thank you,
Ron

[AZRickD]

Whoa !!!

I think I've just witnessed a tear in the space-time continuum.

Rick

[Jeb]

Let's see...the cylinder is aluminum... the lining is what?
What the heck is rusting? I don't get it!

Rick - this info may or may not help - it certainly is an attempt . . .

rusting is oxidation. When iron rusts or is oxidized it's crystal size grows (flakes off in chunks, we've all seen it). On the other hand, when aluminum oxidizes it's crystal size does not grow and that is why corroded aluminum is more of a discoloration.

Corroding aluminum breaking through the liner is unlikely so, yes, the liner's integrity is suspect, like the small amount of Fe in the liner at the surface of the liner is corroding.. . .

OR there IS something that has been deposited. A buildup of some sort on the surface of the liner - all of our liners, over time - is typical, is it not? Something that the rings don't remove thus requiring honing? Couldn't something get trapped in that glaze? You would think that a liner breaking down would be more random . . .

Did you give the Scotchbrite a try? 'Seems like a reasonable thing to try along with some measurements to see if, after the Scotchbrite, metal from the liner was lost and how much (and then you could decide whether to get the expensive work done).

[GS]

I'm seconding all of the above...Jeb, RB, Ski, etc... That doesn't look much like corrosion, or a significant issue when viewed all on its own. Blow-by could create that visual effect. It doesn't *look* like the rings have been in close contact with the wall in that area. However, there isn't clear, corroborating evidence of excessive blow-by on the piston.

Measuring the cyl. would help to see if the shape is correct, or not. My own pretty-careful-type methodology would be to clean it up with the scotchbrite and measure/take a fresh look. The color wouldn't mean much to me...provided the measurements/smoothness/plating was reasonable. I also understand that you have placed the re-build and assessment with the shop, which sorta complicates it a bit, I would guess.

Surely the shop has determined if the plating is intact in that discolored area?? Can you confirm that?

I hear your need for safety in the desert. However, I think we all know that "new" far-too-often doesn't translate to "better" or "safer". Ron's highly experienced comments confirm the thoughts of the others.

Let us know if anything else develops.

Greg

[AZRickD]

The same questions are running through my head as well.

Time for anothe lunch time visit... with magnet and ScotchBrite.

Rick

[IdahoCharley]

I'm seconding all of the above...Jeb, RB, Ski, etc... That doesn't look much like corrosion, or a significant issue when viewed all on its own.

Measuring the cyl. would help to see if the shape is correct, or not. My own pretty-careful-type methodology would be to clean it up with the scotchbrite and measure/take a fresh look. The color wouldn't mean much to me...provided the measurements/smoothness/plating was reasonable.

I hear your need for safety in the desert. However, I think we all know that "new" far-too-often doesn't translate to "better" or "safer". Ron's highly experienced comments confirm the thoughts of the others.

Let us know if anything else develops.

Greg

I cut Greg's response to reflect my feelings on what I can see of the cylinder. I've seen many pulled cylinders but not many with corrosion looking issues.

I do recall an article or two which when talking about cleaning out (honing)the KAW cylinders in particular you need to be sure to get an coat of oil wiped on the cylinder wall right away or it will start to oxidize. (One of Eric Gorr's books mentioned this also - if I recall correctly) I bring this up since it seems to align with what Ron Black also stated.

If it were mine - I would scotch brite the cylinder and then wipe it down with WD-40 until dry and clean - examine the cylinder in very good light to make sure no flaking in the cylinder has occurred. (Do not understand the comments related to roundness of cylinder - but what you are looking at is NOT blowby on the cylinder coating)

If cylinder looks good, (light discolored would be ok with me) and feels smooth with no pitting I would measure the piston to cylinder fit and if acceptable - Re-ring and ride the bike. I would also change out the small end wrist pin bearing for peace of mind.

Breakdowns in the desert or 20 miles from the truck should not result from the above methodology IMHO.

FWIW - I believe like others have stated you have likely had some water condensation issues between the piston rings and the top of the cylinder which resulted in some light corrosion. Is the corrosion significant - only a hands on examination can determine that IMHO. Good Luck

[GS]

IC,
In the spirit of enlightenment, what does blow-by look like in your experience? Reason I ask is that Ive seen similar "brownish" coloring on seriously worn cylinder walls and I may have mistakenly credited it to just that.

After taking a fresh look, it does appear to have the "look" of light corrosion.