Project KDX 220R - The Rebuild

[Slick_Nick]

I'm in the process of rebuilding my 2000 KDX 220, and I thought I would share it here. Plans for the rebuild are fairly mild.

For the chassis, all bearings will be inspected and lubed or replaced, new graphics, seat cover, maybe some fresh paint in areas, everything will be sandblasted to clean it up. Spokes checked, new brake pads, new chain and sprokets, new bars, grips and a new headlight. (Anyone know where I can get a green DHH???)

The engine will recieve a complete rebuild, top and bottom. The countershaft seal is weeping, and the left main seal is leaking a bit too. New rod, main bearings, piston, RB head and carb, and V-Force 3 reed valve to top it all off.

Today began by setting the bike up on my patented stand, and removing all the big stuff. Rear wheel, swingarm, seat, tank, shrouds, rads, blah blah blah... Swingarm bearings and all linkage bearings are ok, just need a thurough cleaning and some grease. I disassembled the rear wheel bearings, cleaned, and repacked. 2 spokes were a bit loose, need to get a spoke wrench and fix that. I'm glad I'm getting new brake pads.

After all the stuff was removed, I pulled the engine and set it on the bench, and left the chassis aside for now.









Started by removing the reeds, one corner was chipped, maybe that's why I'm getting premix before my carb. VF3 will take care of that problem. Plug pulled too, maybe 10 hours on it. Running a touch lean with the cold weather it looks like.







Then, I pulled the head. Was I ever in for a surprise. Looks like the imfamous 220 broken piston a few owners ago, you can see the damage to the head, and where someone tried to grind it out. Hopefully RB Designs can save this head, if not I'll grab a used one.





One of the KIPS shafts was broken, through no fault of my own... Add another part to the list...





Pulled the jug, and to my surprise, it had a Wiseco piston, and not only was the cylinder plating in great shape, apparently one of the PO's "Ryan" had it ported and polished!















I think I know why the jug was in such good shape however. It probably had to be replaced after the piston broke, because the bottom end had been rebuilt as well with a Hot Rods connecting rod, but why the HELL would you not replace the crank too? This bottom end has eaten some metal in its lifetime.









Water pump looks like it had some aluminum lunch too:



Once I put that aside, I pulled the clutch to see if it was FUBAR too. Fiber plates look OK, but the metal ones look overheated. What do you think? Also, are those stock springs? The basket is notched a little bit, I'm gonna shop for a new one.









Overview



And finally, took apart the KIPS. Looks bad, but it opened and closed smooth as silk. I'll clean this up like new!





That's all for day 1, that MGD turned into many after that hahaha.

Keep checking back for updates!

[tony_d123]

Great pics, keep them coming.

[Indawoods]

Clutch plates do look way overheated. Poor crank....

[Slick_Nick]

I'm trying my damndest to source a used crank, but the ones on fleabay are steeply priced. New clutch is on the way (Tusk with EBC springs) and I'm going to file and drill the basket out. (This FRP basket is a myth I think...) Other than that, Wiseco crank bearings, Moose complete gasket kit, a complete bead blast and painting of the engine, should be good to go.

[Slick_Nick]

Another thing, that cylinder is sleeved, I'm guessing because the broken piston ate a hole in the stock aluminum. By the markings on the bottom of the piston, (looks like 770??) is that an overbore? I'll throw a micrometer on it on Monday and measure for sure though. Is that a steel sleeve? Does the porting job look well done?

[Indawoods]

I'd be looking for a replacement cylinder too.... steel means heat.

[Slick_Nick]

Balderdash. The steel sleeve is FAR more durable than the stock aluminum electrofusion, and can actually be repeatedly honed. It's an upgrade over stock, why would I want to get rid of it??

Thoughts on the porting job?

[Indawoods]

Steel ratains heat... and you will be doing more top ends as steel is not electocoated like an aluminum cylinder and wears fast.

Balderdash? Ha!

[canuckhybrid125]

Balderdash. The steel sleeve is FAR more durable than the stock aluminum electrofusion, and can actually be repeatedly honed. It's an upgrade over stock, why would I want to get rid of it??

Thoughts on the porting job?

Nice pictures Nick
Nikasil plating is better than stock plating and like Inda said sleeves add heat.

[Slick_Nick]

Why would I replace something that's perfectly good, and will last longer than the stock electrofusion? Found out the sleeve is cast iron, I could run 100 pistons through that thing before it would need an overbore. Cast iron isn't as good a conductor of heat as aluminum, but it does just fine. Why do almost all factory motocross teams sleeve their engines? Not only to overbore, but it increases longevity as well.

Sorry guys, The sleeve stays. There's more advantages than disadvantages.

[Indawoods]

Longevity and racing bikes are not synonmous ... But personally I really don't care what you do.... proceed and good luck.

[Mr. Wibbens]

It's just a 220, it's not like it can get much worse

[Julien D]

A good aftermarket replate should last for a very long time. Much longer than a steel insert. Plating is very hard, and much more durable than a liner, even the factory plating. It also transfers heat better, and you can run tighter tolerances with plating than with a sleeve. Watch out for that as well. I think Wiseco specs at least .001 extra clearance for a sleeve. They generally aren't cast iron anymore either. LA Sleeves uses carbon chrome, and molybdenum. Tough, but not as tough as Nikasil. A sleeve is NOT an upgrade for a factory plated cylinder. It's a quicker and cheaper (sometimes) way to repair a badly damaged cylinder rather the proper method of welding and re-plating it or replacing it.

re: Why do almost all factory motocross teams sleeve their engines?
Many modern 4 stroke MX bikes have a liner because the cylinder wall is too light and thin to be strong enough on it's own. The liner is necessary for strength, and they are not intended to last very long at all. Especially not a factory race bike.

Maybe do some reading on the subject if you want. Information on sleeves vs. plating is plentiful. Very few people still prefer a sleeve, and for reasons usually personal and unknown to the rest of us. It is true, you can bore and hone a sleeve more easily. That is perhaps the ONLY benefit of an insert. The point of plating though is that you should never have to bore or hone it!

I'm not in any way saying you should replace the cylinder. It looks good, and if it works good, then use it.

Great pics btw, nice to see such clean shots!! And good luck with your build!


J.

[Slick_Nick]

Well, just heard back from Ron at RB designs, he doesn't think the head is salvageable. Looks like I'll have to source one of those too. I hate how the PO thought it was okay to run the bike like this, and I (assuming everything was ok) rode it HARD. I guess it's a true testament to the KDX's strength...

Really on the sleeve vs. plating debate, I appreciate the arguments, but like you said, if it works and works well, just run it, so I will.

No one really commented on it yet, but does the porting job look well done, or half-assed? I wonder who did it? Fredette?

[Julien D]

I can't really tell that it's been ported or not. The ports will require some chamfering when a sleeve is installed, and that may be all that was done. The markings on the bottom of the cylinder look like "Ryan's kdx 220" to me. Just an identifier so they know who to send the jug back to when they're done.

It does look like whoever did the sleeve did a better job than most. Ports are all lined up nice and it hasn't slipped or turned in the bore.


J.

[Slick_Nick]

I know it's ported, pics 15, 16, and 17 show that. I'm just wondering about the quality of the port job.

[skythrasher]

I can't really tell that it's been ported or not. The ports will require some chamfering when a sleeve is installed, and that may be all that was done.

J, I'm with you. Without speaking to the person who did the work or had it done it is impossible to tell if any modifications were done at the time of sleeving.

Installing the sleeve will require chamfering and blending to the cylinder. This blending could have an effect on the porting, however I don't think it would be enough to tell except maybe on a really good engine dyno.

Is it quality work? Well, It appears that the sleeve install was quality. Does it run good? If so call it a good job, if not call it a not so good job.

There mystery solved.

[Slick_Nick]

It ran great! Never had any problems with it whatsoever. The whole reason behind this teardown is that I'm an anal prick that had to fix the tiniest leak in the main seal. That being said, I'm glad I tore it down! :D

[Slick_Nick]

Didn't get much done today, the hockey game was on (stupid USA...) Anyway, took some stuff off the frame, took it outside and hit it with the pressure washer again (I'm THAT anal.) Got into every nook and cranny I could find, this thing is spotless now. I might grab some kawi green spraybomb and touch it up, we'll see.





Then I turned my attention to the swingarm. Took off the chain guide, and chain rub, cleaned both. The Chain guide I hit with some scotch brite to give it that "brushed" look. The chain rub was within spec, so it went back on. I'll be changing the decals to ones from a '98 model (I like the retro neon yellow) and painting the kickstand after I sandblast it.











Onto the linkage bearings, I just greased them 2 months ago, expected them to be okay and they were. Cleaned thuroughly anyway and repacked. Old and shitty:



New and greasy:



The Swingarm bearings on the other hand... Nevermind, new ones are on the way.This is AFTER trying to clean them:



That's all I really had time for, more to come tomorrow.

[Slick_Nick]

Made a bit of headway today. I know alot of people know the cons of painting parts on the bike, and how quick it wears off, I know this, but I also have a sandblaster, so I'm able to do some pretty thurough prep. I honestly dont care if it wears off, I can re-do it anytime. Anyway, I sandblasted and painted alot of the "misc" parts, and hung them to dry. Did the kickstand too, it was looking really rough.







The swingarm was looking like ****. And I knew if I painted it, it would all come off within a ried or two, even with sandblast for prep. So, I removed the decals (replacing them with the neon yellow ones from a '98) hit the swingarm with some crushed glass abrasive, from about 2 feet just to dull the finish, then cleaned it, and drysprayed some color matched silver on. I'm really impressed with how it turned out, and it will last a long time.

Uglyness from when I high sided:



Decal removed:



About 5 drysprayed coats:



Much better!



Then it was onto those damn singarm bearings. After about 30 minutes with emery cloth, I got the through pins looking like chrome again, and then I went to town o nthe bearings themselves. Cleaned, packed, worked grease in, cleaned again, repacked, repeat... You get it. After an hour I got all 4 bearings moving very smoothly again and got all the crud out of them. Saved myself about $80. Nice and greasy:



Cleaned, lubed, and installed the dust seals:



All parts back on, the swingarm is complete. I'll wait until its on the bike to torque the kickstand on.