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Yes, thankfully those marks are from the reflection upon my crappy picture taking skills! There are some spots in question by that exhaust port though. Maybe caused by going to long without new rings?

Fairly common wear... She needs to go in for a replate.

Ouch, yeah. Looks like the plating is gone right there.

thanks for the input. yeap the plating is flaked off a little there but it ain't horrible. I decided that as soon as my head gets back from RBD, I'm going to put it back together and run it.. Its a KDX, it outta be able to run strong for at least another four years after that!

A missing piece of plating will allow your rings to make it worse, tear the rings up, and any displaced metal goes to ? That being said I threw my WR back together like that once, and it ran OK, but I was never expecting any true life out of it before getting tore down to the bottom end.

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bronco95tgp wrote: I decided that as soon as my head gets back from RBD, I'm going to put it back together and run it.. Its a KDX, it outta be able to run strong for at least another four years after that!

bronco95tgp wrote: I'm here for information to help me get my KDX back on the trail in the best shape possible. Simple as that.

best shape possible... on a college student's budget! It'll be aite

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bronco95tgp wrote:Yes, thankfully those marks are from the reflection upon my crappy picture taking skills! There are some spots in question by that exhaust port though. Maybe caused by going to long without new rings?

The area where the plating is gone is a pretty significant area (IMHO) - in addition it looks like there may be significant wear starting right above the exhaust port.

It looks like a case of running a piston too long - too much clearance between cylinder and piston skirt. This allows the piston to cock in the cylinder which forces the rings to become more like scrapers - which can lead to this type of wear and/or ultimately to catching a ring in a port screwing up the barrel and possible the rod.

I agree with Indawood's response.

It's winter...Save the $180 you need to send it to langcourt before putting it back together. Shipping will be cheap as they are darn near local to you. Plating repair should've been priority over head mod. Bare aluminum will disintegrate rapidly in there!! If your on a super-tight budget I'd hate to see your riding season ruined in the middle of next season because you fried your new top end (and worse). Keep your eye out for used cyls on ebay (with clean plating) as well.

What up gangsters?
For the record I had a mechanic at Midway cycle here in town hone that cylinder. The marks in question disappeared and she had a nice cross hatch. The tolerances all checked out so I put everything together and now my bike is starting on the first kick.
I had a complication with the fuel line, I bought some new 1/4in transparent green hose from the local Cycle Gear.. stuff has a pretty thin wall and is hard to keep from getting a kink IMO. Everyone using zip ties instead of the crappy wire clamps from the factory?

Honed it eh?

yea boy, honed and made some good cross hatches for them rings to seat. I didnt take you a picture

I'll try and get ya a couple pics at the supercross race in Atlanta next weekend though.. My buddy's work hooked a few of us up with tickets, pit passes and the works.

bronco95tgp wrote:yea boy, honed and made some good cross hatches for them rings to seat. I didnt take you a picture

I'm sure it made some good cross hatches

I thought you couldn't hone this type of cylinder after it was plated...

You can't. Disappearing wear marks is the bare aluminum blending in with the plating. I'm sure it'll run for a while. At least till the blowby blows out the crank seals.

Theres many ways to deglaze the plated cylinder like theres many ways to skin a cat scheckaet. Some people say you can use anything from tooth paste & tooth brush to a scotch brite & WD40.

The logic I personally support is that you hone a cylinder to create tiny little ridges. These ridges act like a file, and they wear down your rings. This is too eliminate any imperfections on the edges of the rings and they create a good seal. By filing them, you make sure that seat properly against the cylinder wall.

Them little ridges ain't very big, and they're arent very strong either, so they wear down quickly. Basically, while they are scraping against the rings, the rings are scraping back and wearing them down. Eventually, the rings get seated properly, and these ridges are worn down properly, and you get a nice good seal on the rings.

If the ridges stay there forever, they would constantly be scraping and filing your rings down to nothing. So, it seems really unlikely that, even in Nikasil, the ridges are there forever. Otherwise your rings would be worn down to nothing very quickly.

Now, if we assume that those ridges get worn down, then it seems to me that you would need to hone your cylinder again the next time you changed your rings, or else your rings don't get seated properly. What you do is, take the cylinder to an expert and for $15 bucks he wont make any flakes around the ports and you'll be good as new with some nice cross hatches to seat those rings.

Actually, nikasil has lower oil retention than the old iron sleeves. The crosshatching is also there to retain oil on the cylinder walls, not just to seat the rings. You are correct about the rings wearing. The rings do wear against the cylinder walls, that's why they need to be checked/replaced fairly often.

Generally speaking, if the crosshatching is worn off of a plated cylinder, it's time for a re-plate. You are NOT supposed to hone a plated cylinder. You CAN hit it with a silica ball hone or cylinder brush. Neither of those are hard enough to cut into the nikasil plating. Nikasil is extremely hard.

All that aside, i'm sure the bike will run for you for a while, like I said. I've run some pretty beat cylinders and gotten a season out of them. Either way, next time you tear that top end down, be ready for some scary looking parts!

J.

On average, how many hours will a set of rings last in a kdx 220. It has a weisco piston.

I do not know about how many hours you can get out of some rings on a wiseco yet. I had almost 5 years on my stock piston/top end, the bike was starting to take 3+ kicks to start and had crappy power up in high revs, it was also smoking more than normal..

I put my bike together this past week with RB'd head and a wiseco.. put it through some heat cycles then romped on it around the neighborhood yesterday. Got to the staging area for my favorite trail ever today and she cranked on the first kick, everyone was impressed.. The bike is running strong as ever and it even sounds different. Made some gnarly hill climbs and really had a blast with it