KDX Restoration X 2

[ericr]

Wow, I'm a believer now. I had read a little bit about leak down testing but thought, I'm doing a full rebuild with all new seals and gaskets, why do I need to even bother? I'm so glad I did.



I built my own tester from parts from Amazon (parts list below). It took a couple days to get it built because I was threading a NPT hose barb into a thin freeze plug. I knew that there was no way that was going to seal, so I applied a little 3M 5200 that I had stored in the freezer. Normally, it takes 48 hours to cure. It never cured, maybe from being frozen, so I had to start over.

Today, I applied some epoxy and got it cured enough to use. On the first pump up to 6 psi, the gauge dropped and I could hear hissing from around the intake. I brushed some soapy water around the rubber intake and reed block and had bubbles coming out pretty much from all around it.

Between the metal reed block and cylinder, I had put in a new gasket with Gascacinch on one side and grease on the other side of the gasket material. In between the reed block and rubber boot, there is nothing but a molded in o-ring type shape. It obviously was not doing its job. I applied a bead of Ultra Copper, hand tightened the bolts, and waited a couple hours before torquing to spec.

Next pump up with the gauge, I lost about a half pound in 15 minutes. I thought that might be good enough, but I'm sure I would have been troubled about it. I started with the soapy water again, starting with the Kips resonator, and lo-and-behold, there were a couple bubbles. I pulled the cover off and realized that I had not applied grease to the one side of the gasket. After wiping on grease and reassembling, the next pressure test held 6 pounds for an hour!

I am so glad I did this and recommend this to anyone doing a top or bottom end. I feel that I now have a stable platform for carb tuning along with much less chance of seizing.

Time for the engine to go into the frame!









(For plugging the exhaust - you can get these individually at a auto parts store)

(For plugging the intake - sold individually at an auto parts store. I drilled this for the hose barb)

[KDXGarage]

This thread continues to deliver. Period.

[antonyp]

Awesome work on those engines Eric - I wish I could test ride those bikes when they are done [emoji38]

You got me thinking with that leakdown test. I suppose my old lady could do with a checkup [emoji848]

What type of grease do you use for your gaskets/o-rings ?

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[ericr]

Awesome work on those engines Eric - I wish I could test ride those bikes when they are done [emoji38]

You got me thinking with that leakdown test. I suppose my old lady could do with a checkup [emoji848]

What type of grease do you use for your gaskets/o-rings ?

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I just use the Bel-Ray waterproof grease. Just enough to change the color of the gasket material. It seems to make it seal better and allows you to remove a cover without destroying the gasket. For the head and cylinder base gaskets, I use Gascacinch on both sides with the idea that I would never reuse those gaskets.

[ericr]

How much play should there be from side-to-side for the swingarm? After tightening the swingarm bolt and linkage down, the gap between the outside of the swingarm and the frame is quite large.

Using a screwdriver, I can pry the swingarm from left to right by over 6mm with the linkage detached. Is this so it can self-align on the spockets or is my frame tweaked,? I feel like putting some washers in there to tighten things up. Is this normal? I used a Pivot Works bearing kit.

Edit: I took another look at it. Torquing the pivot bolt clamps everything together - bushings and engine case. The movement is from the bearings sliding left to right on their bushings. You would think that there would be some thrust bearings or bushings to limit this movement.

On the 220, the original shock spring had scrapes where the swingarm rubbed on the spring. I thought that this was because of excessive movement but found that some weld beads had not been ground off the swingarm and were contacting the spring. The whole thing seems strange to me, but that's how the factory designed it and other than filing down the welds, I'll leave it that way.

[ericr]

I got tired of parts cleaning tonight so I decided to take some photos. Here's an update;

Engines are in the frames...



I got the back brakes done. It took about 12 hours to disassemble, clean, etch, clear coat, reassemble and install. I added the Devol disk guard. I had wanted to get a Scotts Fin, but after a recent post on this forum, all remaining inventory sold out. I contacted Scotts and they have no immediate plans to make more.



I added a Works Connection rear caliper guard to the 220 since the stock one was broken. The brake lines are Core Moto. The calipers have All Balls rebuild kits and new pads installed.



Here's the master cylinder with the guard installed. The master used a ProX rebuild kit. I found that the circlip included with the kit for the plastic feed elbow was too small. Make sure you keep the original clip in good shape. The brake pedal was painted with Rustoleum Aluminum. I know, the cotter pin is loose and on the wrong side - I'm waiting to make final adjustment. I also added IMS Pro footpegs.



On the other side, I added a Fredette Racing chain guide, new chain slider, Vortex 50 tooth sprocket, Primary X-ring chain, and new sprocket bolts that were in a bolt kit. Just by chance, the chain is the same color as my hubs.



And finally, one last shot of the master cylinder. I like these Core Moto brake lines. They fit perfectly and are less expensive than some alternatives. That's it for now. I have front brake parts in the parts cleaner waiting for me.

[KDXGarage]

Looks good!

Thanks for the update.

[lucy]

Too pretty to ride...

What is your wife/mother/GF/significant other going to say when you keep it in the living room?

[ericr]

Too pretty to ride...

What is your wife/mother/GF/significant other going to say when you keep it in the living room?

I would expect something like, "That's nice dear."

[B737driver]

Too pretty to ride...

What is your wife/mother/GF/significant other going to say when you keep it in the living room?

I would expect something like, "That's nice dear."

Well I can assure you that my wife would divulge some expletives. My ‘87 CR lived in the living room of my apartment back in the day...I love the smell of premix in the morning...and evening...all day for that matter.

Enjoying the updates. You’re getting close.

[ericr]

I ran into a little roadblock. I was finishing up the front brakes and found that the caliper won't fit on the 220. After thinking about it, I should have known and anticipated this. The 220 is using a '98 KX250 front hub and rotor. The caliper holder bracket is the same for the KDX and my KX250 forks. It's the caliper itself that has different part numbers. I'll have to order a salvaged caliper on ebay and a rebuild kit and pads.

[ericr]

Based upon several threads on this subject, I bought 2, KX125 kick start levers to install on the bikes. They are both from 1993 which fits the suggested range of 92-98. I also bought the KX250 boss, P/N 13061-1692. They don't fit. The 250 boss is 1.2mm shorter than the 125 boss. This makes the bolt groove on the boss not line up with the retaining bolt. The only way I see to fix this is to file 1.2mm off the bottom of the levers. This makes the seal groove 1.2mm too shallow for the seal. I guess I could find an o-ring to work. How have others made this work?

[Slick_Nick]

I wrote a tutorial on the KX 125 kick on the KDX it lists all the part numbers.

[ericr]

I wrote a tutorial on the KX 125 kick on the KDX it lists all the part numbers.

Yes, I saw your post along with some others and a Youtube video. They all said to use a 92-98 KX125 kick lever and that 13061-1692 KX250 boss. I must be the only one having problems, but here's a picture. It's too short to clear the bolt.



I checked Partzilla - 92-98 all have the same part number for the lever. I bought 2 levers from different sources on ebay, both 93's, and they are identical. The part number is 13064-1158 for the assembly for all of those years. You can see that bolt, 92009, it won't slide through the groove in the boss because of the difference in height, it would have to be forced.



I'm just going to file down the bottoms to get clearance and find an o-ring to replace the seal. Just a heads-up to anyone else who might have this problem.

[ericr]

I filed down the kick levers 1.2mm and they work fine now. On to carbs.

Here's the float bowl level gauge I built. It's a old drain plug from ebay, a brass plumbing sleeve with JB Weld, and some tubing. I'll use it to check that using my credit card gauge to set the floats to 18mm brings the gas level up to the mating flange.

I also added a JD Jetting air screw for under $15 (sorry Ron), and the zip tie to tighten up the worn choke knob.



Rb Designs rejetted the carbs. This one, the 220, has a 40 pilot, CEK-3 needle, and 150 main. After reading posts on this forum, I changed the needle to a DEK and am trying to decide clip positions. I think I'm going to first try clip 3. If I get a lean bog, I'll go up to 4. Here's a couple comparisons of the two clip positions to CEK-3. I'm also going to run 40:1 which will richen things up a bit. My feeling is that I'd rather go a little bit lean in that 1/4 throttle area than immediately spooge up my new silencer - but, I'll check my plug in that throttle range right off.

[Vossman]

This post is epic. Bike looks great, can’t wait to see the complete build.

[John_S]

I love this post also!! Regarding the needles, you mentioned above that you want to be leaner at 1/4. According to the Keihin needle chart, my own experience with C vs D testing, and other members posts over the years, a DEK is richer than a CEK at 1/4 - 3/4. James Dean (JD Jetting) said his red needle is similar to a CEL and the blue needle is similar to a DEL. I run the JD jetting and the instructions state that the blue needle is to richen the carb at 1/4 throttle.

[ericr]

I finished with the carbs. I checked the shop manual again about setting float bowl fuel level. They give 2 methods; The first is setting the float height to 16mm +2. From other's experience, 18mm seems optimal. The second method is to measure the fuel level using a sight tube. The manual specs a fluid level even with the mating flange +2mm. The +2mm must equate with a 16mm float height.

Being even with the flange matches a 18mm float height.

Based upon the experiences of several others on this forum, I set my DEK needles on clip 4, and installed the carbs.

I installed lots of other items too. In fact, all that's left now on the 220 is a Moose pipe guard, plastic and decals and it's done. The 200 will be about a week behind. Oh, and I have some 1/4" UHMW sheet stock that I was going to fabricate into linkage guards, but that can wait.

Here's some photos;






I said that I like the Core Moto brake lines. You can adjust the position of the rubber ferrules by sliding them. I slid it to fit right in the lower clamp. On the top, I trimmed 1" off the outer sheathing to get a perfect fit. I also tried vinyl wrapping for the first time with the 3M 1080 vinyl in carbon print for the upper fork tubes. I kinda like it. I covers up a lot of rock chips on 20 year old forks.




Rather than just removing it, I trimmed the airbox lid to retain that vertical lip in hopes of at least diverting some water.



I like this Trail Tech Endurance. I had to cut a little channel out of the foam in the bar pad to get it to fit. I think I'm going to order another one for the 200.



One last thing I'm waiting for is a 1998 KX250 front disk. After ordering that salvaged caliper, cleaning and rebuilding it, it still didn't fit. I thought the guy on ebay sold me a wrong fitment. I then decided to measure the disk and found that it's 10 mm too large in diameter! That disk came with the used KX250 hub I had purchased. I just assumed that it was the correct one. The replacement comes next Monday. Next week, this bike will be complete!

[KDXGarage]

It looks great! Thanks for the follow ups!

[jstcraig]

Really enjoying this post, lots of fine work going into this build and some excellent ideas to be considered for the novices on the forum [emoji1303][emoji1303]


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