HopFrog's 1980 KDX175 Build Log

Discussion specific to the various air-cooled KDX models sold in the USA
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Re: HopFrog's 1980 KDX175 Build Log

Post by HopFrog175 » 11:12 pm Feb 15 2021

The last swing arm related item is the rear chain guard which is in pretty bad shape. Same story as the front chain guide - fix and wait for a used one. Or, maybe go for one of those nifty looking aluminum units. They are easy to replace so I will run the patched up old one for a bit - it looks pretty iffy though so it may not last too long!


Patching the old broken chain guard
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kdx175_chainguard_01.jpg
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kdx175_chainguard_02.jpg
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kdx175_chainguard_03.jpg
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kdx175_chainguard_04.jpg
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hf175w.jpg
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Last edited by HopFrog175 on 12:03 am Feb 16 2021, edited 2 times in total.

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Re: HopFrog's 1980 KDX175 Build Log

Post by HopFrog175 » 11:56 pm Feb 15 2021

One more post for the long weekend - putting stuff together :grin: I cleaned up the rest of the frame first, did not see any cracks. I will do a careful check before going much further, cracks have a way of sneaking in. Re-assembly was straight forward. I never did find acceptable boots for the rod-ends of the upright links. If I do find some, I will have to take the links loose again to install.

Swing arm and shock in place
_click image to zoom_
kdx175_rear_suspension_01.jpg
kdx175_rear_suspension_01.jpg (257.05 KiB) Viewed 143 times

I was a little worried about if the swing arm would tighten properly. I had to cut the substitute needle bearing sleeve length from 53.8mm to 52mm. I came in close but not exact so tightening the swing arm pivot could either bind or leave a little axial, side-to-side, slop.

Tightened the axle and the swing arm felt fine, woo hoo!! :supz:


Swing arm and shock
kdx175_rear_suspension_02.jpg
kdx175_rear_suspension_02.jpg (267.68 KiB) Viewed 143 times

Rear suspension re-assembled
kdx175_rear_suspension_03.jpg
kdx175_rear_suspension_03.jpg (262.4 KiB) Viewed 143 times
Well, it looks like it will work and compression/rebound feel good!

Earlier I noted that after pressing the new joints into the rocker arm, the ball joints felt pretty stiff. Then, I noticed this while leafing through the manual:


New Spherical Bearings may be Stiff
kdx175_rear_suspension_04.jpg
kdx175_rear_suspension_04.jpg (104.64 KiB) Viewed 143 times
One less thing to remember to worry about :-)
hf175w.jpg
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Last edited by HopFrog175 on 12:12 am Feb 16 2021, edited 1 time in total.

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Re: HopFrog's 1980 KDX175 Build Log

Post by KDXGarage » 12:04 am Feb 16 2021

and prudently!! That's pretty much how I ride. :-)

Looking good!
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Re: HopFrog's 1980 KDX175 Build Log

Post by HopFrog175 » 02:08 am Feb 22 2021


Now that the rear suspension is operable, on to the wheels. The rear wheel does not look too bad but that is because it is only 30 years old (as opposed to the front's 40 years)! When I got this bike, it came with a pretty good dent in the rear rim so, at the time, I had a local shop lace up a new rim with new spokes. Still, this is one part I am not looking forward to mainly because some of the spokes are probably rusted in place.


Rear wheel and Brakes
_click image to zoom_
kdx175_rear_wheel_01.jpg
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Pulled the brakes out to find lots of rust on the inside of the drum. Hopefully it is more of a surface rust variety.


Rusty rear brake drum
kdx175_rear_wheel_02.jpg
kdx175_rear_wheel_02.jpg (215.59 KiB) Viewed 120 times


It looks like the brake shoes have turned to goo - nothing a little replacing and cleaning can't fix up :grin:


Rear backing plate and shoes
kdx175_rear_wheel_03.jpg
kdx175_rear_wheel_03.jpg (281.23 KiB) Viewed 120 times


The torque link needle bearing in the hub is rusted up. I will hunt for a replacement.


Torque link needle bearing caught some rust!
kdx175_rear_wheel_04.jpg
kdx175_rear_wheel_04.jpg (170.13 KiB) Viewed 120 times


Actually the wheel bearings came out pretty easily with a little hammering. Surprise! There are 3 of them - 2 are the same size and one is larger. One of the small bearings feels good but the other two are not as good so I might as well replace all 3. When I went to order, All Balls indicated out of stock - front and rear. So, I figured that as long as I am tracing down the torque link needle bearing, I might as well check for alternative wheel bearing sources. Wheel bearings (unlike those odd suspension ball joints) are usually a common size.


Rear wheel bearings
kdx175_rear_wheel_05.jpg
kdx175_rear_wheel_05.jpg (243.82 KiB) Viewed 120 times

Next, I will find out what's available and make up a chart with sources.

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Re: HopFrog's 1980 KDX175 Build Log

Post by KDXGarage » 02:32 am Feb 22 2021

If you take the bearings out, throw them out. Replace with new, even if they feel like they are still good.

On that drum, get one of those three spring rectangular brake hone things. It is kind of like a drill bit with three grinding stones.

DO NOT grind those old shoes, as they may have asbestos. I worked on a buddy's 1983 QT50, and it had asbestos shoes.
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Re: HopFrog's 1980 KDX175 Build Log

Post by HopFrog175 » 02:56 am Feb 23 2021

^^^
Thanks, KDXGarage - new bearings and shoes are definitely called for!


KDX175 Wheel Bearing Details

I pulled the wheel bearings out and checked my replacement options - here is what I found.

Quick list
Feb 22, 2021


OPTION 1
--------
Complete set, front
    source - AllBallsRacing.com - $15.63
      https://www.allballsracing.com/25-1184.html

Complete set, rear
    source - AllBallsRacing.com - $21.05
      https://www.allballsracing.com/25-1055.html

total for AllBallsRAcing - $36.68


OPTION 2
--------
Individual Bearings
(priced each)                                                                     Timken
                    Part numbers                                                   from
            ------------------------------                   Part-   Kawasaki     Quality
Size        Kawasaki    General  Timken*    #  Description   zilla   Parts House  Bearing
----------  ---------   -------  ---------  -  ------------  ------  -----------  -------
12x32x10mm  601B6201U   6201     6201-ZZ    1  front, right  $14.77  $12.10       $10.28
12x37x12mm  601B6301U   6301     6301-ZZC3  1  front, left   $24.36  $24.95       $12.34
17x35x10mm  601B6003U   6003     6003-ZZC3  2  rear, right   $17.51  $15.06       $11.64
20x42x12mm  601B6004UU  6004     6004-ZZ    1  rear, left    $28.82  $24.40       $12.46

*"Timken Deep Groove Radial Ball Bearings, metal seals"

totals for 5 bearings (2 front, 3 rear)                      $97.97  $91.57       $58.36

Links:

Front, right bearing sources 
https://www.partzilla.com/product/kawas ... 05f2d980b4
https://www.kawasakipartshouse.com/oemp ... =601b6201u
https://www.qualitybearingsonline.com/6 ... 2x32x10mm/


Front, left bearing sources
https://www.partzilla.com/product/kawas ... 05f2d980b4
https://www.kawasakipartshouse.com/oemp ... =601b6301u
https://www.qualitybearingsonline.com/6 ... 2x37x12mm/


Rear, right bearing sources (2 bearings are required on the rear, right)
https://www.partzilla.com/product/kawas ... 53d8deda86
https://www.kawasakipartshouse.com/oemp ... =601b6003u
https://www.qualitybearingsonline.com/6 ... 7x35x10mm/


Rear, left sources
https://www.partzilla.com/product/kawas ... 53d8deda86
https://www.kawasakipartshouse.com/oemp ... 601b6004uu
https://www.qualitybearingsonline.com/6 ... 0x42x12mm/
 


When I checked, AllBallsRacing was out of stock for the kdx175 and that was when I searched out the options listed above. I figured an extra $20 was worth it for Timkens and the order went out.
hf175w.jpg
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Re: HopFrog's 1980 KDX175 Build Log

Post by KDXGarage » 04:22 am Feb 23 2021

I raise my beer to you, sir. Shopping well done.

Get a new circlip for the rear.
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Re: HopFrog's 1980 KDX175 Build Log

Post by HopFrog175 » 01:32 am Feb 24 2021

KDXGarage wrote:
04:22 am Feb 23 2021
I raise my beer to you, sir. Shopping well done.

Get a new circlip for the rear.

Excellent suggestion on the circlip, thanks, I was totally overlooking!

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Re: HopFrog's 1980 KDX175 Build Log

Post by HopFrog175 » 02:18 am Feb 24 2021


More progress to update, nothing exciting as I am still on the wheels, bearings and brakes.


Front wheel bearing removal
_click image to zoom_
kdx175_front_wheel_01.jpg
kdx175_front_wheel_01.jpg (282.99 KiB) Viewed 109 times

I had already knocked out the front/rear wheel bearings and ordered Timkens so figured it was time to slip off the 30-year old tire carcasses. Hah, what a aggravation, the tires had shrunk and were rigid as stone :mad: In retrospect, I should have cut them off but, at the time, I just kept levering. They eventually came off and I am hoping I did not bend anything (like the rim).


Removing the 30-yr old rear tire
kdx175_front_wheel_02.jpg
kdx175_front_wheel_02.jpg (469.68 KiB) Viewed 109 times

After letting some Kroil soak in, I checked over the spokes. Mostly straight with a couple of rusty ones. Good news in that I was able to get all of the spoke nipples to turn :grin:


More rust removal needed
kdx175_front_wheel_03.jpg
kdx175_front_wheel_03.jpg (176.06 KiB) Viewed 109 times
Each spoke nipple turned!
kdx175_front_wheel_04.jpg
kdx175_front_wheel_04.jpg (379.75 KiB) Viewed 109 times

Once I get the new wheel bearings installed, I can break out the dial indicator and true 'em up. I think the rear is ok (it was never run) but the front is unknown. It looks ok, as I recall, but, worst case, I could be doing some lacing.

At this point, I am starting to think about Tires. Everyone I talk to and every post I read has a different opinion - what to do? What little dirt experience I have is out of date and I do not even recognize half of the tire brands :hmm:

I'm in the SoCal area so expect to be mostly on dry, hard packed with some rockiness. Probably places from San Diego to Mojave.

Then, I saw Tubeliss - tubeless on a spoked rim. Sounds great and the vids, while mixed a bit, mostly look good. You gotta have decent tires, so now I am thinking Tubeliss with some grippy tires.

I am seeking tire suggestions and will read up some more, then make a list of candidates - any advice is welcomed!

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Re: HopFrog's 1980 KDX175 Build Log

Post by KDXGarage » 04:37 am Feb 24 2021

Sir, step away from the adjustable wrench. YOU DON'T HAVE TO DO THIS!! :-)

Please get a spoke wrench. :prayer:

Nice cart and casters to the left! :bravo:

Congratulation on getting all the nipples to turn.

I have a 1993 KX125 somewhere around here. Using a green Scotch-Brite pad on the spokes worked great. I was quite surprised.

I am digging that Sun rim.

If you don't go Tubliss, I suggest a couple of runs of duct tape around the rim to keep the water out (after they are perfectly trued of course). This is vs. a normal rim strip.
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Re: HopFrog's 1980 KDX175 Build Log

Post by Goofaroo » 06:53 am Feb 24 2021

If you’re gonna ride mostly hard pack and rocks you don’t necessarily need knobbies. A dualsport tire would last longer, grip better, and ride smoother. I tried a few tires when I started going on adventure rides. I settled on Shinko 700s and have never looked back. Everything is always a trade off but if I knew that a majority of my trail riding would be on hard pack and rocks I would use them on my dirt bikes. They’re all I use on my KLR250 and KLR650.

Here’s a link just as an example. They can generally be had for around $100 for both tires.
https://www.motosport.com/product/?cc=u ... -X001-Y001

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Re: HopFrog's 1980 KDX175 Build Log

Post by HopFrog175 » 03:32 am Feb 25 2021


Thanks for the feedback, good point on the spoke wrench! My old spoke torque wrench wandered off somewhere, I will have to put a new one one the get-now list.

Tires are still up in the air and Goofaroo, you gave something new to consider, thx. Next step is to look up some old pals who are dirt bike riders and get some recommended riding areas and decide knobbies or dualsport. I will have to figure out stickers too.

---

Progress-wise, the front brakes are ready and the drums are half-way done.


Cleaned up front brakes
_click image to zoom_
kdx175_front_brakes_01.jpg
kdx175_front_brakes_01.jpg (340.26 KiB) Viewed 83 times

Front brakes
Brakes together. (Don't worry, I got that spring all the way in after the taking the photo :-)
kdx175_front_brakes_02.jpg
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Cleaned up the odometer drive
kdx175_front_brakes_03.jpg
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Greased and ready
kdx175_front_brakes_04.jpg
kdx175_front_brakes_04.jpg (125.78 KiB) Viewed 83 times


Odometer drive is ready but ... no odometer, it was missing when I got the bike. I am keeping an eye out for one that's working and can always figure a way to go digital if I end up really needing something.

And, finally, after finding the drum measured within tolerance, I spent some time spinning and sanding. This takes a while but almost there :grin:
(I wasn't able to find the 3-legged hone mentioned earlier)


De-rusting the brakes
kdx175_front_brakes_05.jpg
kdx175_front_brakes_05.jpg (186.68 KiB) Viewed 83 times

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Re: HopFrog's 1980 KDX175 Build Log

Post by KDXGarage » 05:40 am Feb 25 2021

Man. You just keep showing out. :grin:

It is nice to see such parts without a decade or more of brake dust caked up everywhere.

I may be remembering this wrong, but did you put a little dab of grease where the springs contact the shoes and where the shoes contact the cam and pivot? Are we supposed to do that?? :hmm:

I broke out the Clymer manual for 82 - 91 KX125 / KX250 and some KX500's. They said grease the cam flat part and pivot, but didn't say anything about the spring ends. I am at halfway remembering things at least. :mrgreen:

I do like the homemade lathe and brake drum turning machine. :bravo: Here's a link to one I have and used on a Yamahopper QT50. I guess it would need to be a bigger one to work on a big bike.

https://www.lislecorp.com/specialty-too ... brake-hone
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Re: HopFrog's 1980 KDX175 Build Log

Post by HopFrog175 » 03:31 am Feb 27 2021


Wheel progress continues with the new Timkens installed and brake drums cleaned up as much as I can do by hand, I think that they will be ok although the rear still has a bit of visible pitting (you can see it but can't feel it).


Rear wheel bearings installed
_click image to zoom_
kdx175_rear_wheel_re-assembly_011.jpg
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Here is a close up of the pitting - if I get any pulsation, I will have to pull it apart and either get it turned or get a replacement hub. Of course, if I have to pull it back apart, it could also be a good excuse for swapping in an aluminum swing arm ,,, :wink:


Rear drum with some pitting
kdx175_rear_wheel_re-assembly_014.jpg
kdx175_rear_wheel_re-assembly_014.jpg (122.9 KiB) Viewed 71 times

On to a rim runout check on the rear. Not too bad (considering my wrestling match to get the 30-yr old rear tire off):


Rear radial runout check
kdx175_rear_wheel_re-assembly_016.jpg
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Rear axial runout check
kdx175_rear_wheel_re-assembly_018.jpg
kdx175_rear_wheel_re-assembly_018.jpg (176.7 KiB) Viewed 71 times
  • Radial - 0.006" (0.080" max)
  • Axial - 0.022" (0.120" max)



I might tweak it just a hair (once I get that spoke wrench) in one spot where it twitches out. The front remain to be seen. I am also waiting on new hub circlips (thx KDXGarage) and the torque link needle bearing, so, all that's left is sanding the brake shoes to fit a little better. Then on the front wheel.

Any down time waiting for parts will give me time to do some more reading on tires. Plus, before too long (summer?) I need to round up some dirt gear :grin:


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Re: HopFrog's 1980 KDX175 Build Log

Post by KDXGarage » 06:36 am Feb 27 2021

As usual, great work!

Check the rear sprocket for warp while you are back there on that rim.

Don't be afraid to check it again after a ride or two in case the spokes set in a touch.

Get a clip on that odo drive, too. :-)

On gear, don't be afraid to spend the money. YOU ARE WORTH IT!

In order:
helmet, goggles, boots, other stuff
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Re: HopFrog's 1980 KDX175 Build Log

Post by HopFrog175 » 12:12 am Mar 01 2021


Wow, I took a close look at the front rim and it is actually pretty bad :shock: One good dent and wobbly all over the place, way past spec. I see that some un-dent rims with a big crescent wrench. I am thinking of trying Tubeliss, tho, and would hate to find them unable to seal on a beater rim.

Plus, with a good rear rim already in place, I hate to have a bad front. The rear is a Sun that I got new last century when I bought the bike. It did not occur to me until after I started researching replacement front rims but - Sun rims are still available :grin: Even better, when I saw that the manufacturer (Buchanan's) is in Azusa, just an hour's drive, it became clear that the front rim should match the rear rim. I will have to make a trip out there sometime in March.

I've got plenty else I can do before finishing the wheels/tires, forks next I guess, then engine seals.

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Re: HopFrog's 1980 KDX175 Build Log

Post by KDXGarage » 06:10 am Mar 01 2021

WOW! Congratulations on just being an hour away from them.

A matching set of rims would be nice.
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