HopFrog's 1980 KDX175 Build Log

[HopFrog175]

Well, after a long break, I think it is time to finish this job The back-story my post over in the Introduction forum is that I started in on this 1980 KDX175 back last century. Today, I pulled it out to take a look, here is where I am (re)starting:

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I rebuilt the motor back in 1991 so figure I will pull it apart for new seals. I might replace the clutch while I am in there. The rest of the bike, I will tackle and try to focus on one step at a time. Made some room and and utilized a spare bucket:

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Step one accomplished: into the shop and ready to start work

[KDXGarage]

Thanks for taking us along with you. Good luck.

[kick]

Have fun bringing that bike back to life.

[HopFrog175]

Where to start? Seems like I was contemplating the rear suspension when I last turned a wrench on this project. Checking just now, yup, that slop I remember is still there.

I sprayed all of the bolts with Kroil (I hope Kroil is still in business, my can is pretty old) the other day as some looked pretty rusty.

Started by removing the shock and then wondered if it would still function so I pulled the spring off:

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The shaft is pitted from rust

The shock on the KDX175 is crimped at the top leaving nothing to unscrew. Disassembly of the shock body might be possible but likely not worth the time and effort. Working up to 2000 grit made an improvement to the shaft, hopefully good enough - we will see. Once smooth, I was able to compress it - still has pressure!! After 40 years - amazing.

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Still, it would be nice to have an update. But how? No direct replace shock is to be found as far as I can tell. That leaves a custom shock which would blow my budget so, for now, the old one will be given another chance. (If anyone knows of a close fit from another bike, please let me know!)

Cleaned up and greased the threads on the body and rings then reassembled.

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[KDXGarage]

Good job on the shock. It is not made to be a serviceable shock. Either buy a custom new one or roll the dice on another used one off eBay.

[HopFrog175]

With the shock out of the way, time for the rear suspension to come off, one rusty bolt at a time. Actually they were ok, spraying with Kroil must have helped. Rocker removed and on bench:
_click any image to zoom_

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The ol' Whipple-built press from Smith River, c.1960, pushing the old bearings out:

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And here are the new bearings Woot!! Woot!! I managed to snag these off ebay over the last year or so in anticipation of this project. Afaik, these are unique to the kdx175. Normally I would cruise by a bearing shop in Burbank to see if there was a match but when these came up, I took the lazy way out. Probably a few more $$ but no worries on fit. (I will post a parts list with sources in a later post.)

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Gotta get them started straight before pressing, much easier this way:

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Rocker arm cleaned up with new bearings in place (old bearings, on top, get saved, of course)

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I greased the new bearings but the ball-joints are pretty stiff. I guess this is good (no slop) and they will loosen up in use.
The links to the swing arm will be next.

[KDXGarage]

You must be a millionaire. Three new OEM bearings! Those things are NOT CHEAP when one can find them.

Good job on the shopping even more than the mechanical work. Seriously.

[HopFrog175]

Thanks! I shop slowly but to the point - "Millionaire", haha! Actually, when I lack time to work on a project (too often), I try and prep for it. In this case, I had time to wait until the right parts appeared at a price I could afford. From ebay, the two outer bearings came at $32 each shipped and the center bearing at $60 shipped. Then they sat for a few years patiently waiting for their new home. I think I have a lot of what I need but will find out what's missing as I go.

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[KDXGarage]

You are welcome. I have done a bit of "for the future" shopping as well, especially a decade ago before eBay sellers jacked the prices of NOS items through the roof.

Keep up the great work!

[Goofaroo]

The first thing that I bought on EBay was a clutch basket for my 85 model XR350R. That was over 20 years ago and I still have it on hand if I ever need it. lol

I’m tagging along on your build. It’s nice to see one of the early models brought back to life.

[HopFrog175]

On to the rear suspension links connecting the rocker to the swing arm, Simple but, err, the bolts turn out to be rust-welded to the ball of the ball-joint. Judicious pounding and prying did not budge either bolt.

_click to zoom images_

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A little additional persuasion did the trick. This was the hardest thing to get apart so far.

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Cleaned up and ready for new ball joints (another ebay purchase from last year).

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All together with greased balls and anti-seized threads. I am missing the rubber ball-joint covers. Any that have turned up were way too much for a 40-year old piece of rubber - I may have to try and make substitutes up out of neoprene tubing or something

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Cleaned up the bolts and crossed one more item off of the list

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[KDXGarage]

Man. Looking good! Again, good job.

[HopFrog175]

Thanks, I am trying to maintain the survivor patina, no powder coating or perfect glossy paint allowed!

I already have the swing arm off so might as well start in. It looked pretty neglected and rusty but seems solid enough:

_click to zoom images_

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The swing arm bearings were pretty well stuck. And, the swing arm would not fit far enough into the press - it is a great little press for a homebuilt but goes have its limitations - so I moved to Plan B:

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Cleaned the worst of the dirt and loose rust off

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Added just a little touchup - rust marks on a faux aluminum swing arm just didn't look right so I spritzed on a bare minimum of dull aluminum spray paint.

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Ready for the next step: installing new swing arm bearings.

[KDXGarage]

The weight of that steel swingarm must be up there. :-) I bet it is sturdy, though.

[HopFrog175]

KDX175 suspension rebuild details

Having just rebuilt the rear suspension on my 1980 KDX175, a write up is called for First, many thanks to mlyle11's thread: KDX 175 suspension rebuild from a few years back, I am basically just adding some details to that very helpful writeup. I will start with a quick list and then follow up with all the gory details.

Quick list
Feb 9, 2021

59266-1001 - 2 required - Rocker arm ball joint
    source - ebay               -  $30-$60 availability and price vary
    source - CMSNL.com          - $127 each
     https://www.cmsnl.com/kawasaki-kdx175-a1-kdx175-1980-usa-canada_model15171/joint-ball-suspension_592661001/
    source - PartNumberPros.com -  $69 each
     https://partnumberpros.com/products/kawasaki-59266-1001-suspension-ball-joint-kx-kdx?_pos=2&_sid=130a03c74&_ss=r

92028-1087 - 1 required - Rocker arm center bushing/sleeve bearing
    source - ebay               -  $30-$60 (availability/price vary)
    source - CMSNL.com          - $120 each
     https://www.cmsnl.com/kawasaki-kdx175-a1-kdx175-1980-usa-canada_model15171/bushing-suspension_920281087/

59266-1002 - 2 required - Suspension up-right rod-end
    source - ebay               -  $30-$60 (availability/price vary)
    source - CMSNL.com          - $102 each
     https://www.cmsnl.com/kawasaki-kdx175-a1-kdx175-1980-usa-canada_model15171/joint-ball-suspension_592661002/
    source - Bearing Supply #1  -  $12 each
     https://www.qualitybearingsonline.com/pos12ecl-qbl-left-hand-maintenance-free-type-with-male-thread
    source - Bearing Supply #2  -  $13 each
     https://www.vxb.com/POS12-Male-Rod-End-12mm-Right-Hand-Bearing-p/kit12360.htm

92046-1031 - 2 required - Swing arm needle bearing
    source - ebay               -  $20 (availability/price vary) search for 20x27x30mm needle bearing
    source - CMSNL.com          -  $23 each (availability varies)
     https://www.cmsnl.com/kawasaki-kdx175-a1-kdx175-1980-usa-canada_model15171/bearing-hmk2030-needl_920461031/
    source - Bearing Supply #1  -  $10 each
     https://www.vxb.com/TA2030-Needle-Roller-Bearing-20x27x30-Metric-p/kit21216.htm

42036-1031 - 2 required - Swing arm, sleeve for needle bearing 
    source - ebay               -  $30 (availability/price vary)
    source - CMSNL.com          -  $37 each (availability varies)
     https://www.cmsnl.com/kawasaki-kdx175-a1-kdx175-1980-usa-canada_model15171/sleeve-swing-arm_420361031/

Alternative sleeve - requires cutting length to size of 52mm
42036-1031 - 2 required - Rocker arm bushing/sleeve for 1999-2003 kx125, kx250
    source - ebay               -  $20-30 (availability/price vary)
    source - CMSNL.com          -  $11 each (availability varies)
     https://www.cmsnl.com/kawasaki-kx125-l1-1999-usa-canada_model11928/sleeve_420361357/
 

That's it! More or less expense and hassle depending on your time factor. Naturally, use best practices when buying from un-vetted sources and evaluate the suitability of each part before use.

Details

Next, more details on the KDX175 rear suspension joints than you ever wanted to know :-) Measurements were made directly off of the parts by me and are not exact. Also, I measured in inches and converted to mm, sometimes putting down the number I already knew to be correct, e.g. I knew that the swing arm sleeve has a 20mm OD even though the measured inches converted to 19.9mm. For Bearing suppliers, sources, I looked at a fair number but many more exist. If possible, visit one in your neighborhood with your old bearing; they know a lot more than I do and may be able to get the parts. The Rocker arm ball joints and the center bushing/sleeve are just plain unusual, though, with the 27.5mm outer diameter. I did not find any matches but if all else fails, a bearing supplier may be able to get one with a 28mm OD and you could have the rocker bored to match. Same with the center bushing/sleeve. For the rod-ends, variations exist with zerk fittings and some kind of sealing or cover. Different styles of rubber rod-end covers are available on ebay too and it seems like at least one style might work although they all look bulkier than the originals. As for wheel bearings, that are commonly available so I did not include them in the list.


Rocker arm ball joint
Id x od x width (ball width) ===> 14mm x 27.5mm x 17mm
_click to zoom images_

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Rocker arm center bushing/sleeve bearing
Id x od x width (sleeve width) ===> 14mm x 27.5mm x 17mm

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Suspension up-right rod-end
Id x thread length x width (ball width) ===> 12mm x 36mm x 16mm (12mm threads)

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Swing arm needle bearing
Swing arm, sleeve for needle bearing
Id x od x width (bearing width) ===> 20mm x 27mm x 30mm
Id x od x width (sleeve width) ===> 15mm x 20mm x 52mm

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Alternative - REQUIRES CUTTING LENGTH TO 52mm
Rocker arm bushing/sleeve for 1999-2003 kx125, kx250
Id x od x width (sleeve width) ===> 15mm x 20mm x 53.8mm

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That's it - Whew!!

[KDXGarage]

a tidal wave of awesomeness has hit the KDX175 beach

What an excellent post! Thank you for sharing the information with the world!

[HopFrog175]

Glad to contribute, I had to do something before I forgot everything :-) And, now I can proceed with finishing my swing arm. Due to not-so-good luck and timing, I was unable to find any swing arm needle bearing sleeves (had not found them at CMSNL.com yet) SO i bought 1999 KX125 Rocker arm bushing/sleeves off ebay and cut them to 52mm. Lacking any real machine tools, I had to jury-rig a Dremel.


The kx125 rocker sleeve is 1.8mm too long
_click image to zoom_

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Cutting the kx125 rocker sleeve from 53.8mm to 52mm

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The sleeves are now 52mm and ready for a little breaking of sharp edges with the grinder

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The needle bearings pressed in without a fuss

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One shim rolled away. I really searched but had to go to Ebay for the rescue (a $10 slip up I did not need).


Ready for grease and assembly

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Just a couple of more bits and the swing arm will be ready to re-install.

[KDXGarage]

As before, excellent work. I can even read the words more easily. Thanks for the "large print" edition.

[bufftester]

Nice write up and great luck on finding those bearings, they are unobtanium for the most part.

[HopFrog175]

Two more small swing arm items starting with the chain guide. For a 41 yr-old piece if rubber, it is not too bad except for a crack.


Original chain guide with a nasty crack
_click image to zoom_

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That crack is pretty deep but really would not hurt if it went all the way through. Still, I thought repair or replacement wouldn't hurt. The NOS replacements are pricey so I went for the repair.

Dug around and found that CD Drive cover that I'd been saving and cut it too size.



Cutting a CD drive cover plate to cover the chain guide crack

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A little bit of hammering got it to fit over the distressed area


Test fitting the cover

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Once the cover fit, I coated the crack and area with epoxy and stuck the cover on.


Cover epoxied into place

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Here is the repaired chain guide in place on the swing arm.


Swing arm

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Hopefully this will keep the chain guide going while I wait for an affordable replacement to come up. Plus, next time I find myself at a worldwide kdx175 gathering, I will have the benefit of easily picking my bike out of the bunch